User’s Guide Third Edition (January 2004) Part Number: 360226-001
© Copyright 2003 Hewlett-Packard Development Company, L.P. Hewlett-Packard Company makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hewlett-Packard shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.
Table of Contents Preface .........................................................................................................................................i Intended Audience ....................................................................................................................................i Organization of This Guide ......................................................................................................................i Conventions Used in This Guide .................
Chapter 3: Text Clients ...........................................................................................................3-1 The Text Client ........................................................................................................................3-1 Starting the Text Client ........................................................................................................................................................................ 3-1 Using the Text Client .................
Chapter 6: Connections ...........................................................................................................6-1 Connection Options .................................................................................................................6-2 Throughput Diagnostic Utility ................................................................................................6-3 Connection IDs .................................................................................................
Chapter 8: Replication .............................................................................................................8-1 Replication Options ..................................................................................................................8-1 How Replication Works ...........................................................................................................8-1 Recovery From Network Losses ............................................................................
Pausing Storage Mirroring Execution on the Target .......................................................10-14 Pausing through the Management Console ..................................................................................................................................10-14 Pausing through the text clients ......................................................................................................................................................
Chapter 13: Monitoring Tools ...............................................................................................13-1 Management Console Tools ..................................................................................................13-2 Management Console statistics ......................................................................................................................................................... 13-2 At-a-Glance monitoring ...........................................
Appendix B: Application Failover .......................................................................................... B-1 Script Sample ........................................................................................................................... B-2 Appendix C: Disaster Recovery for MSCS ............................................................................ C-1 Cluster Configurations ...................................................................................................
Preface Preface Intended Audience The intended audience for the Storage Mirroring User’s Guide is network administrators with expertise in Windows. The network administrator should be responsible for setup and maintenance of the network and should have working experience installing, configuring, and maintaining network applications. Organization of This Guide Each chapter in this guide is organized in primarily the same manner.
Online References The online manual and online help provide a means of accessing product information. The online help for the Management Console, Failover Control Center, and Text Client are automatically installed with the Storage Mirroring client components. The manuals are also automatically installed. Online help The online help requires a version 4 or later browser (version 4.5 or later is better).
1 ! Introduction to Storage Mirroring Introduction to Storage Mirroring HP OpenView Storage Mirroring is a real-time data replication and failover software product. Storage Mirroring augments your existing data protection strategy by reducing downtime and data loss, and it provides these services with minimal impact on existing network and communication resources.
Storage Mirroring Features Storage Mirroring has high availability and disaster recovery management features, resource utilization features, multi-platform features, improved backup benefits, among other features. High availability and disaster recovery management features ! Continuous, transaction level replication reduces your network’s exposure to data loss by immediately replicating file changes to the target machine.
Storage Mirroring Operations Storage Mirroring performs four basic types of operations: ! Mirroring—The initial copy or subsequent resynchronization of selected data ! Replication—The on-going capture of byte-level file changes ! Failure monitoring and failover—The ability to monitor and stand-in for a machine, in the event of a failure ! Restoration—A mirror of selected data from the target back to the source Each operation is briefly described in the following sections.
Replication Replication is the real-time transmission of file changes. Unlike other related technologies, which are based on a disk driver or a specific application, Storage Mirroring’s replication process operates at the file system level and is able to track file changes independently from the file’s related application. In terms of network resources and time, replicating changes is a more efficient method of maintaining a real-time copy of data than copying an entire file that has changed.
Failure monitoring/failover Failover is a process in which a target machine stands in for a failed source machine. As a result, user and application requests that are directed to the failed source machine are routed to the target machine. Storage Mirroring monitors the status of machines by tracking network requests and responses exchanged between source and target machines. When a monitored machine misses a user-defined number of requests, Storage Mirroring assumes that the machine has failed.
Restoration Restoration provides an easy method for copying replicated data from the target back to its original location on the source. The process only requires you to select the source, target, and the appropriate replication set. There is no need to select files or to remember where the data came from on the source since that information is maintained by Storage Mirroring.
Sample Configurations Storage Mirroring is an exceptionally flexible product that can be used in a wide variety of network configurations. To implement Storage Mirroring effectively, it is important to understand the possible configuration options and their relative benefits. Storage Mirroring configuration options can be used independently or in varying combinations. NOTE: Storage Mirroring’s replication and failover features have different machine requirements.
One-to-One, Active/Active Replicated Data 1 Source Data 1 Source Data 2 Replicated Data 2 Target and Source Machine (Active) Source and Target Machine (Active) Description Each machine acts as both a source and target actively replicating data to each other. Applications This configuration is appropriate for failover and critical data backup. This configuration is more cost-effective than the Active/Standby configuration because there is no need to buy a dedicated target machine for each source.
Many-to-One Source Machine Source Machine Source Machine Target Machine Description Many source machines are protected by one target machine. Application This configuration is appropriate for offsite disaster recovery. This is also an excellent choice for providing centralized tape backup because it spreads the cost of one target machine among many source machines. Considerations The target machine must be carefully managed.
One-to-Many Source Machine Target Machine Target Machine Target Machine Description One source machine sends data to multiple target machines. The target machines may or may not be accessible by one another. Applications This configuration provides offsite disaster recovery, redundant backups, and data distribution. For example, this configuration can replicate all data to a local target machine and separately replicate a subset of the mission-critical data to an offsite disaster recovery machine.
Chained Source Machine Target and Source Target Machine Machine Description One or more source machines sends replicated data to a target machine that in turn acts as a source machine and sends selected data to a final target machine which is often offsite. Applications This is a convenient approach for integrating local high availability with offsite disaster recovery. This configuration moves the processing burden of WAN communications from the source machine to the target/source machine.
Single Machine C:\Data D:\Data Replication Set Data Copy of Replication Set on Specified Target Path Source and Target Machine Description Source and target Storage Mirroring components are loaded on the same machine allowing data to be replicated from one location to another on the same volume or to a separate volume on the same machine. These could be locally attached SCSI drives or Fibre Channel based SAN devices.
2 ! Management Console Management Console The Management Console is a 32-bit GUI client that can manage and monitor Storage Mirroring components on any platform. Storage Mirroring machines are displayed along with active connection information. The Management Console can also configure failover settings. NOTE: You may not have access to some of the components or see certain display options if you are using a newer version of the Management Console to control an older version of your source or target.
Understanding the Display The left pane is a tree view displaying each machine running Storage Mirroring. As each machine name is highlighted, note the following items: ! The status bar at the top of the pane displays the modules loaded on each machine: Source, Target, Source and Target, or None. (None indicates that the core functionality of Storage Mirroring is running, but neither the source nor target modules have been loaded.
! After you have logged into a machine, a collapsable and expandable tree view of the volumes and directories it contains is displayed. To expand the tree, click on the plus sign icon. To collapse the tree, click on the minus sign icon. ! The right pane displays the following information depending on the item selected in the left pane of the Management Console and the tab selected on the right pane.
Management Console toolbar The following icons appear in the Management Console toolbar.
Logging On and Off of Storage Mirroring To ensure protection of your data, Storage Mirroring offers multi-level security using native operating system security features. Privileges are granted through membership in user groups defined on each machine running Storage Mirroring. To gain access to a particular Storage Mirroring source or target, the user must provide a valid operating system user name and password and the specified user name must be a member of one of the Storage Mirroring security groups.
Stopping the Service To stop the Storage Mirroring service from the Management Console, right-click the machine name on the left pane of the Management Console and select Shutdown. Storage Mirroring Ports Both the Management Console and the Storage Mirroring server use ports to communicate with each other. Management Console ports The Storage Mirroring Management Console uses two ports for Storage Mirroring communications.
Storage Mirroring server ports The Storage Mirroring service uses three ports for Storage Mirroring communications. ! Service Listen Port—The Storage Mirroring server uses this port to listen for commands from other Storage Mirroring servers. ! Heartbeat Transmit Port—The Storage Mirroring server uses this port to transmit heartbeats. ! Staus Listen Port—The Storage Mirroring server uses this port to listen for requests to update at-a-glance monitoring from the Storage Mirroring Management Console. 1.
Inserting a Server If a machine is not displayed on the Management Console, it can be manually inserted. This feature is useful for machines that are across a router or on a different network segment. These types of machines will not automatically appear in the Management Console because the UDP heartbeat is not passed by the router.
Storage Mirroring Workspaces The Management Console workspace contains the display of the panes of the Management Console and any servers that may have been inserted. Multiple workspaces can be used to help organize your environment or to view settings from another machine. Saving a workspace As you size, add, or remove windows in the Management Console, you can save the workspace to use later or use on another Storage Mirroring client machine.
3 ! Text Clients Text Clients The Double-Take Command Language (DTCL) is a scripting language that can be used in either the Text Client or Command Line Client to manage and monitor Storage Mirroring components. It can also be used in script files to execute series and combinations of commands to meet specific needs. Because the Text Client and Command Line Client use the same DTCL commands, all examples use the Text Client.
The Command Line Client The Command Line Client can be run from a command prompt. It can manage and monitor Storage Mirroring components on any platform regardless of the Command Line Client platform. The Command Line Client is run from the operating system command line and the DTCL commands are run from the Storage Mirroring command line.
Logging on and off of Storage Mirroring To ensure protection of your data, Storage Mirroring uses native operating system security and requires a valid system username and password. If you do not have a valid system username and password for a selected machine, you will not be able to configure Storage Mirroring for that machine. As you enter DTCL commands, Storage Mirroring automatically attempts to log on to the source or target machine. You can verify your access by the resulting message.
Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options ! machine—Name of the machine ! username—Name of the user ! password—Password associated with username. ! domain—If logging in using a domain account, this is the domain name. If logging in using a local account, this is the machine name.
Specifying Source and Target Functionality If you did not specify your machine as a source or target when starting the Storage Mirroring you will need to load the modules using the DTCL commands load source or load target.
Storage Mirroring Ports Both the text clients and the Storage Mirroring server use ports to communicate with each other. Text client ports The Storage Mirroring text clients use two ports for Storage Mirroring communications. ! netport—The text clients use this port to send commands to a Storage Mirroring server. ! unetport—The text clients use this port to listen for heartbeats sent from a Storage Mirroring server. 1.
Storage Mirroring version 4.3 Source Machine: indy (Access Level: FULL) ================================================================================ Command: ================================================================================ > setlocal netport = 1110 3. To determine the current unetport setting, use the get command with the unetport option. The default port number is 1100. 4. To modify the unetport, use the set command with the unetport option.
Storage Mirroring server ports The Storage Mirroring service uses two ports for Storage Mirroring communications. ! netport—The Storage Mirroring server uses this port to listen for commands from a Storage Mirroring text client. ! unetport—The Storage Mirroring server uses this port to send heartbeats to Storage Mirroring clients. 1. To determine the current netport setting on a Storage Mirroring server, use the get command with the netport option. The default port number is 1100.
Getting Help in the Text Clients A listing of the DTCL commands and their syntax is available in the Storage Mirroring Text Client and Command Line Client by typing the help command. Command HELP Description Displays the DTCL commands and their syntax Syntax HELP Notes ! Press any key to scroll through the list of commands. ! Press q to exit the help function.
4 ! Failover Control Center Failover Control Center The Storage Mirroring Failover Control Center is the client that controls all aspects of Storage Mirroring failover. The other clients control different subsets of the failover features. ! Management Console—This client can configure the failover settings. ! Text Client—This client can configure the failover settings and can control the failover processes.
Understanding the Display The Failover Control Center’s main window controls three types of failover activities: ! Identifying what the target is monitoring ! Configuring failover operations ! Monitoring failover activity Identifying what the target is monitoring The two main areas of the Control Center screen are the Target Machine selection and the Monitored Machines/Names pane.
Monitoring failover Now that replication and failover monitoring are configured and started, you will need to know if and when there is a problem. Since it can be essential to quickly know the status of your machines, Storage Mirroring offers various methods for monitoring the status of failover.
The following table identifies how the visual indicators change as the status of failover changes. Time to Fail Countdown Source is Online Source Fails and Failover is Initiated Failover is Complete Status Bar Colored Bullets Desktop Icon Tray The Time to Fail counter is counting down and resetting each time a heartbeat is received from the source machine. The status bar indicates that the target machine is monitoring the source machine. The bullets are green.
Communication Ports The Storage Mirroring service and the Failover Control Center use two ports for various Storage Mirroring communications. ! ! Service Transmit Port—The Failover Control Center uses this port to send commands to Storage Mirroring servers. Heartbeat Listen Port—The Failover Control Center uses this port to listen for heartbeats transmitted from Storage Mirroring servers. To view or modify the port settings in the Failover Control Center, select Settings, Communications.
5 ! Replication Sets Replication Sets A replication set defines the data on a source machine that is to be protected by Storage Mirroring. Replication sets are defined by the volumes, directories, files, or wild card combinations that are to be replicated to the target. Creating multiple replication sets allows you to customize sets of data that need to be protected. Replication Set Rules Replication sets are created by defining rules.
Replication Set Operations The following replication set operations are available: ! Create—You can create replication sets through the Management Console or the text clients by selecting icons through the graphical interface or by specifying explicit paths through any of the clients. ! Modify—Replication set modifications are a dynamic process. While Storage Mirroring is replicating, changes can be made to a replication set that is in use.
How Replication Sets Work To better understand how replication sets work, the following diagram identifies the steps involved with creating and saving a replication set as well as what happens to the replication set information after a source and target have been connected. Each numbered step is described following the diagram. 1 4 2 3 5 Replication Set 1 Replication Set 2 Replication Set 3 Source SourceMachine.db 6 Target 1. The Storage Mirroring client manages all replication set modifications.
Replication Capabilities Storage Mirroring replicates all file and directory data stored on any Windows file system (FAT, FAT32, NTFS4, and NTFS5) with the following exceptions: NTFS extended attributes, registry hive files, and the Windows pagefile. Replicated items also include Macintosh files, compressed files, NTFS attributes and ACLs, dynamic volumes, and sparse files. Files can be replicated across mount points, even though mount points are not created on the target.
Managing Replication Sets Through the Management Console The following sections describe how to manage replication sets through the Storage Mirroring Management Console. Each section assumes that you have already logged into the source machine. Creating a replication set 1. You can use either of the following methods to create a new replication set when a source machine is highlighted: ! Select Insert, Replication Set from the menu bar.
3. To see the directory tree for the source machine selected, expand and collapse the directory structure in the left pane of the Management Console by clicking on a box containing a plus sign to expand the tree and a box containing a minus sign to collapse the tree. NOTE: 4. Define the data to be protected by selecting volumes, drives, directories, and/or specific files by marking the check box next to the desired selection. NOTE: 5.
Creating a replication set using wild cards and direct rule entry In some instances, data may need to be replicated that cannot be easily selected from the Management Console, or the directories or files may not exist. For example, Storage Mirroring’s wild card capabilities and flexible file selection process allows you to manually include all .db files from a specific directory that is otherwise excluded. This flexibility is available through the Replication Set Properties dialog box. 1.
Calculating replication set size While Storage Mirroring is mirroring, the right pane of the Management Console displays statistics to keep you informed of its progress. If the size of the replication set is determined before the mirror is started, Storage Mirroring can display the percentage of the replication set that has been mirrored in the Mirror Status column. If the size was not calculated prior to starting the mirror, the column displays Mirroring.
Modifying a replication set Storage Mirroring allows you to make modifications to a replication set when you want to change the data you wish to protect. This allows you to add, remove, or modify any replication set rules without having to create a new replication set. 1. In the left pane, highlight the replication set you want to modify and expand the volume and directory levels as needed. 2.
Managing Replication Sets Through the Text Client The following sections describe how to manage replication sets through the Storage Mirroring text clients. For a complete list of the DTCL commands, see Storage Mirroring Commands on page A-1. Each of the following commands assumes that you have already logged on and identified a source machine. Creating a replication set 1. Use the repset create command to create a new replication set.
3. Define a replication set rule by using the repset rule add command. Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names.
Calculating replication set size While Storage Mirroring is mirroring, the Text Client displays statistics to keep you informed of its progress. If the size of the replication set is determined before the mirror is started, Storage Mirroring can display the percentage of the replication set that has been mirrored. If the size was not calculated prior to starting the mirror, it displays Mirroring. You can calculate the replication set size manually or on connection. 1.
b. To modify whether or not the replication set size will be calculated when the connection is established, use the set command with the CalculateOnConnect option. The CalculateOnConnect option is set to 1 for enabled or 0 for disabled. By default, the replication set size will be calculated. Command SET Description The Text Client/DTCL sends a request to Storage Mirroring to modify the value of a Storage Mirroring program setting.
Modifying a replication set Make modifications to a replication set when you want to change the data you wish to protect. 1. View the replication sets associated with the active source machine by using the repset list command. Command REPSET LIST Description Lists all replication set names for the currently selected source Syntax REPSET LIST Storage Mirroring version 4.
Storage Mirroring version 4.3 Source Machine: indy (Access Level: FULL) Replication Set: exchange C:/ C:/exchsrvr C:/exchsrvr/bin (press any key) *Modified* exclude recursive include recursive exclude recursive > repset display 4. Remove the existing rule that you need to change using the repset rule remove command.
5. Add a new rule by using the repset rule add command. Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names. Syntax REPSET RULE ADD [INCLUDE|EXCLUDE][, RECURSIVE|NONRECURSIVE][TO ] Options 6.
Deleting a replication set 1. View the replication sets associated with the active source machine by using the repset list command. Command REPSET LIST Description Lists all replication set names for the currently selected source Syntax REPSET LIST Storage Mirroring version 4.3 Source Machine: indy - List of rep sets exchange (press any key) (Access Level: FULL) * DATABASE HAS BEEN MODIFIED * disabled > repset list 2. 3. Delete the replication set by using the repset delete command.
6 ! Connections Connections The Storage Mirroring connection is the link between the source replication set and a target machine. It is a logical connection and refers to the relationship between the replication set on the source and the copy of the data on the target, as well as the status of the connection. The different connection states are described below. Connection Status Description Started The network connection exists and is available for data transmission.
Connection Options When establishing a connection, you must specify the machines that are involved with the connection, what data is being protected and where that data is going, as well as configuring how this connection will perform. ! Source Server—You must specify the Storage Mirroring source machine that contains the replication set that is going to be transmitted to the Storage Mirroring target.
! Start Replication on Connection—Replication can be initiated immediately when the connection is established. If replication is not configured to start automatically, you must start it manually after the connection is established or set a schedule to start it later. NOTE: If you disable Start Replication on Connection, you will need to perform a mirror prior to beginning replication to guarantee data integrity.
How Connections Are Established To better understand how Storage Mirroring connections work, the following diagram identifies the sequential steps completed when establishing a Storage Mirroring connection. Each numbered step is described below the diagram. 1 2 Replication Set Replication Set Backup 4 3 Transmission Queues 5 Source Target 1.
Queuing During the Storage Mirroring installation, you identified the amount of disk space that can be used for Storage Mirroring queuing. Queuing to disk allows Storage Mirroring to accommodate high volume processing that might otherwise fill up system memory. For example, on the source, this may occur if the data is changing faster than it can be transmitted to the target or on the target, a locked file might cause processing to backup. The following diagram will help you understand how queuing works.
Auto-Disconnect and Auto-Reconnect While disk queues are user configurable and can be extensive, they are limited by the amount of physical disk space available. If the amount of disk space specified for disk queuing is met, additional data could not be added to the queue and data would be lost. To avoid any data loss, the auto-disconnect and auto-reconnect processes occur. Source—If disk queuing is exhausted on the source, Storage Mirroring will automatically start disconnecting connections.
Managing Connections Through the Management Console The Management Console can be used to establish, disconnect, and monitor a connection between the source replication set and a target machine. In addition, the Management Console can be used to configure queuing and auto-reconnect.
5. Select the target path, which corresponds to the desired location on the target where the replicated data will reside, by selecting One-to-One or All-to-One. If you want to specify a custom location, select either of the radio buttons and then click on the directory entry under the Target Path column. You will be in edit mode and can specify the desired location on the target for the replicated data. 6.
Monitoring a connection You can monitor an established Storage Mirroring connection by viewing the connection statistics and/or the connection display. These are not the only methods available for monitoring an established Storage Mirroring connection. For information on all of the monitoring methods, see Monitoring Tools on page 13-1. Connection statistics 1.
Connection display You can monitor the connection by understanding the different icons displayed in the Management Console. ! Established Connection Status Icon—The source/target connection status appears as an icon to the left of the replication set name. (If you have reordered the connection data items displayed, the icon will appear to the left of the first column that is displayed.
Configuring queuing There are five queuing parameters available for configuration. 1. Right-click a source machine and select Properties. 2. Select the Queue tab. 3. Specify the Folder which will store the queue. For best results and reliability, you should select a dedicated, non-boot volume. The queue should be stored on a fixed, local NTFS volume. 4. Specify the Maximum system memory for queue. This is the amount of Windows system memory, in MB, that, when exceeded, will trigger queuing to disk.
Configuring auto-reconnect If Storage Mirroring is stopped on a source machine while a Storage Mirroring connection is active, auto-reconnect will automatically reestablish the connection, without manual intervention by the administrator, when the Storage Mirroring source is available. When an auto-reconnect is performed, you may want to perform an auto-remirror to guarantee data integrity. Use the instructions below for both the auto-reconnect and auto-remirror options. 1.
Managing Connections Through the Text Client For each of the connection related commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Establishing a new connection 1.
Options ! ! repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address ! MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the target (c:\data and d:\files is copied to c:\data and d:\files, respectively) ! MAP BASE—The replication set data will be sent to the locations specified below: ! connect repset to target—If mappings are not specified with the command, map base will be us
Connecting to the Throughput Diagnostics Utility To initiate a connection to the Throughput Diagnostics Utility, use the connect to tdu command. This logs the connection statistics to the file specified. The remaining connection flags are identical to the standard connect command.
Monitoring a connection Storage Mirroring offers a variety of methods for monitoring a Storage Mirroring connection. Statistics include information like connection up-time, target status, bytes queued or sent, etc. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Configuring queuing There are five queuing parameters available for configuration. Use the get and set commands to view or modify an option. See Storage Mirroring Commands on page A-1 for complete command syntax. ! QJournalDir—This is the location where the queue is stored. For best results and reliability, you should select a ! QJournalFileSize—This is the size, in MB, of each queuing transaction log file. By default, the file size is 5 MB.
Configuring auto-reconnect If Storage Mirroring is stopped on a source machine while a Storage Mirroring connection is active, auto-reconnect will automatically reestablish the connection, without manual intervention by the administrator, when the Storage Mirroring source is available . When an auto-reconnect is performed, you may want to perform an auto-remirror to guarantee data integrity. Use the instructions below for both the auto-reconnect and auto-remirror options. 1.
7 ! Mirroring Mirroring Mirroring is the process of transmitting the data contained in a replication set from the source to the target machine so that an identical copy of data exists on the target machine. All file and security attributes are also mirrored to the target machine. Mirroring must occur initially to generate a baseline copy from the source to the target. After mirroring has occurred, replication maintains an identical copy of the data on the target.
File Differences Mirror Options Block Checksum File Differences Only if Source is All Server Newer Mirroring Properties Source Mirroring Option Taba Option (!) (!) Block Checksum Mirroring Option ! Any file that is different on the source and target based on the date, time, and/or size is transmitted to the target. The mirror sends the entire file. ! Any file that is newer on the source than on the target based on date and/or time is transmitted to the target. The mirror sends the entire file.
Stopping and Pausing Mirroring While a mirror is in progress, you can manually stop or pause the transmission of data to the target. The Storage Mirroring connection will remain intact and the mirror data may or may not queue on the source depending on the option you choose. ! Pause and Resume—When pausing a mirror, Storage Mirroring stops queueing mirror data on the source but maintains a pointer to determine what information still needs to be mirrored to the target.
Auto-Remirror When a source machine fails, the auto-reconnect feature will reestablish the source/target connection when the source is back online. The auto-remirror option will then initiate the mirror process to synchronize the files on the source and target machines. For more information on source machine failures, see Auto-Disconnect and Auto-Reconnect on page 6-6 . When a target machine fails, the Storage Mirroring source maintains the source/target connection and queues replication data.
How Mirroring Works To better understand how Storage Mirroring mirroring works, the following diagram identifies the different steps that are completed when a mirror is performed. Each numbered step is described below the diagram. 1 Files Contained In Replication Set Identical Copy Of Replication Set 3 2 4 Source Target 1. Mirroring is initiated by the user, either manually through one of the clients or automatically when the connection is created. 2.
Managing Mirroring Using the Management Console Through the Management Console, a mirror can be initiated upon connection, manually controlled, and monitored. In addition, the Management Console can be used to configure orphan files and to automatically run an auto-remirror after an auto-reconnect to ensure that data is identical on the source and target. Initiating a mirror upon connection 1.
Controlling a mirror manually After a connection is established you can manually start, stop, pause, or resume mirroring. Right-click the connection on the right pane of the Management Console and select Mirroring and the appropriate mirror control. ! ! Start—If you select to start a mirror, you will need to make the following two selections on the Start Mirror dialog box: ! Type of Mirror—Specify the type of mirror, Full or File Differences, you wish to perform.
Monitoring a mirror 1. To view the connection on the Management Console, highlight the source machine on the left pane and the connection will appear on the right pane. Use the horizontal scroll bar at the bottom of the right pane to view the Mirror Status column; the status of the mirroring operation for this connection is displayed. The possible states are: ! Idle— No mirroring activity is taking place.
Configuring orphan files 1. You can configure orphan files when establishing a connection or after a connection has been created. ! If you have not yet established a connection, follow the procedures as described in . ! If you want to configure the orphan files setting on an established connection, right-click the connection on the right pane of the Management Console and select Connection Manager. ! If you want to configure orphan files during a restoration, select Tools, Restoration Manager.
Setting auto-remirror In the event of a source machine failure or if the Storage Mirroring service stops, data integrity between the source and target cannot be guaranteed. To resolve this issue, the Storage Mirroring auto-reconnect process automatically reestablishes any source/target connections that existed prior to Storage Mirroring being unavailable. After an auto-reconnect, an auto-remirror will ensure that data is identical on the source and target machines.
Managing Mirroring Using the Text Client For each of the mirroring commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Initiating a mirror on connection 1. 2.
Options ! ! repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address ! MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the target (c:\data and d:\files is copied to c:\data and d:\files, respectively) ! MAP BASE—The replication set data will be sent to the locations specified below: ! connect repset to target—If mappings are not specified with the command, map base will be us
Controlling a mirror manually Identify the connection ID by locating the number in the left column below the target machine name and use one of the following commands for the appropriate mirror control: ! Mirror Stop Command MIRROR STOP Description Stops a paused mirror Syntax MIRROR STOP Options ! con_id—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs ! mirror stop 1 mirror stop * Examples ! ! Mirror Start Command MIRROR START Descri
! Mirror Pause Command MIRROR PAUSE Description Pauses a mirror that is in progress Syntax MIRROR PAUSE Options ! con_id—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs. ! mirror pause 1 mirror pause * Examples ! ! Mirror Resume Command MIRROR RESUME Description Resumes a paused mirror Syntax MIRROR RESUME Options ! con_id—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs.
Monitoring a mirror Storage Mirroring offers a variety of methods for monitoring Storage Mirroring mirroring. Statistics include information like connection up-time, target status, bytes queued or sent, and so on. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Configuring orphan files 1. To determine the current orphan files setting, use the get command with the MoveOrphanedFiles option. By default, orphan files are not deleted. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
6. To modify the location of renamed orphan files, use the set command with the MoveOrphansDir option. This option accepts any valid volume and directory. By default, the directory is the same drive where Storage Mirroring is running in a directory called \RemoveOrphans. NOTE: If you are moving files, make sure the directory you specify to move the files to is not included in the destination of the replication set data so that the orphan files are only moved once. 7.
Setting auto-remirror In the event of a source machine failure or if the Storage Mirroring service stops, data integrity between the source and target cannot be guaranteed. To resolve this issue, the Storage Mirroring auto-reconnect process automatically reestablishes any source/target connections that existed prior to Storage Mirroring being unavailable. After an auto-reconnect, an auto-remirror will ensure that data is identical on the source and target machines.
8 ! Replication Replication A file change, also called a file request or operation, is the creation, modification, or deletion of a file. This also includes file attribute and permission changes. Replication is the real-time transmission of these file changes as they occur. The file changes are replicated from the source to the target, maintaining an identical copy of data on the target machine.
Recovery From Network Losses Storage Mirroring handles packet losses on the network as well. Storage Mirroring verifies the incoming sequencing before looking at execution ordering. Here is an example. 1. The source sends packets 1, 2, 3, and 4 to the target. 2. The target receives packet 1. It expects 1, so it passes the operation to the holding/execution handlers and sends its acknowlegement of packet 1 back to the source. 3. Packet 2 is lost on the network. 4. The target receives packet 3.
Managing Replication Through the Management Console Using the Management Console, replication can be initiated upon connection, manually controlled, and monitored. In addition, Windows permissions can be replicated by name and task commands can be inserted in the replicaiton queue. Initiating replication upon connection 1. There are four methods available for establishing a connection and opening the Connection Manager: ! Highlight a replication set and select Tools, Connection Manager.
Controlling replication manually To stop and start replication for an established source/target connection, right-click the connection on the right pane of the Management Console and select Replication and the appropriate replication control. NOTE: If you stop replication manually, you will need to perform a remirror when it is restarted. If you only need to temporarily pause data from being transmitted to the target and do not want to stop replication, select Transmit, Pause.
Replicating permissions by name 1. To determine if Windows security is being replicated by name, right-click a source machine and select Properties. 2. Select the Source tab. ! If the Replicate NT Security by Name is marked, this feature is enabled and the local security ID is being replicated to the target. You will want to enable this feature if you are using local security groups.
Processing task commands Task command processing is a Storage Mirroring feature that allows you to insert and run tasks at various points during the replication of data. Because the tasks are user-defined, you can achieve a wide variety of goals with this feature. For example, you might insert a task to create a snapshot or backup on the target after a certain segment of data from the source has been applied on the target. 1. To process a task, you must first enable task command processing.
Managing Replication Through the Text Client For each of the replication commands, first identify which source you are working with by using the source command. Command SOURCE Description Identifies a machine as the active source machine Syntax SOURCE Options source_machine—Name of the machine Examples source indy Initiating replication on connection 1. 2.
Options ! ! repset—Name of the replication set target_machine—Name of the target machine, an IP address on the target machine, or a virtual IP address ! MAP EXACT—Specifies that the replication set data will be sent to the same logical volume on the target (c:\data and d:\files is copied to c:\data and d:\files, respectively) ! MAP BASE—The replication set data will be sent to the locations specified below: ! connect repset to target—If mappings are not specified with the command, map base will be us
Controlling replication manually Identify the connection ID by locating the number in the left column below the target machine name and use one of the following commands for the appropriate replication control: ! Replication Start Command REPLICATION START Description Initiates the replication process Syntax REPLICATION START Options ! conid—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs ! replication start 1 replication start * Examples !
Monitoring replication Storage Mirroring offers a variety of methods for monitoring Storage Mirroring mirroring. Statistics include information like connection up-time, target status, bytes queued or sent, and so on. The informational data includes processing notifications, warnings or errors. Below is a brief description of how four of the monitoring methods are applicable to the Storage Mirroring connection. For detailed information on these and other monitoring methods, see Monitoring Tools on page 13-1.
Processing task commands Task command processing is a Storage Mirroring feature that allows you to insert and run tasks at various points during the replication of data. Because the tasks are user-defined, you can achieve a wide variety of goals with this feature. For example, you might insert a task to create a snapshot or backup on the target after a certain segment of data from the source has been applied on the target. To process a task, enable task command processing and then use the queuetask command.
4. Use the queuetask command to places task(s) in the replication queue inline with current processing. Command QUEUETASK Description Queues tasks inline with replication data. Syntax QUEUETASK TO ONQUEUE = [args] | ONTRANSMIT = [args] | ONRECEIVE = [args] | ONEXECUTE = [args] [TIMEOUT = ] [INTERACT | NOINTERACT] Options ! job_name—Any name that you have assigned to the job.
Notes ! The default setting for this command is nointeract. ! Any combination of one or more execution points can be used with the same queuetask command. ! All processing messages, including errors, can be viewed in the Storage Mirroring logs and the Windows Event Viewer. ! Onqueue will still execute as soon as the task is placed on the queue even if transmission is stopped (manually stopped or paused, unmet scheduled transmission criteria, etc.).
9 ! Verification Verification Verification is the process of confirming that the data on the target is identical to the data on the source. Verification creates a log file detailing what was verified as well as which files are not synchronized. If the data is not the same, Storage Mirroring can automatically initiate a remirror. The remirror ensures data integrity between the source and target.
Remirror Options When Verifying Block Checksum Remirror All Server Automatical Properties Source ly Verify Option Taba (!) (!) ! (!) Only if Source is Newer Verify Option Block Checksum Verify Option Action Performed ! Any file that is different on the source and target based on the date, time, and/or size is transmitted to the target. The mirror sends the entire file. ! Any file that is newer on the source than on the target based on date and/or time is transmitted to the target.
Verification Log A verification log is created on the source during the verification process. The log identifies what is verified as well as which files are not synchronized. The options and defaults are listed below. ! File Name and Location—By default, the verification log is called DTVerify.log and is stored in the same directory as the Storage Mirroring program files. ! Append or Overwrite—By default, the log is appended each time a verification process is completed.
How Verification Works To better understand how Storage Mirroring verification works, the following diagram identifies the steps involved with the Storage Mirroring verification process. Each numbered step is described below the diagram. 1 Files Contained In Replication Set Replicated Files 4 2 5 3 Source Target Verification Log 1. Verification is initiated by the Storage Mirroring administrator, either manually through one of the clients or automatically through a scheduled verify. 2.
Managing Verification With the Management Console In the Management Console, verification can be configured when a connection is established or it can be initiated manually at any time while a connection is active. Configuring verification on connection 1. There are four methods available for establishing a connection and opening the Connection Manager: ! Highlight a replication set and select Tools, Connection Manager. ! Right-click on a replication set and select Connection Manager.
Initiating verification manually 1. To initiate verification manually, right-click the connection on the right pane of the Management Console and select Verify. 2. Select the verification options that you would like to perform. ! Verify Only—This option performs the verification process by comparing the date, time and size of each file and generates a verification report identifying the files that are not synchronized.
Verification log A verification log is created during the verification process. The log details what is verified as well as which files are not synchronized. Use the following steps to set up your verification log in the Management Console. NOTE: All changes to a verification log should be made on the source side of a connection. 1. Right-click a source machine on the left pane of the Management Console and select Properties. 2. Select the Logging tab. 3.
Monitoring verification To view the connection on the Management Console, highlight the source machine on the left pane and the connection will appear on the right pane. Use the horizontal scroll bar at the bottom of the right pane to view the Mirror Status column; the status of the mirroring operation for this connection is displayed. The possible states are ! Idle— No mirroring or verifying activity is taking place.
Managing Verification Using the Text Client In the Storage Mirroring Text Client, verification can only be initiatied after a connection is established. Initiating verification 1. Log on to the source using the login command. Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options ! machine—Name of the machine ! username—Name of the user ! password—Password associated with username.
3. Identify the connection ID by locating the number in the left column below the target machine name and initiate the verification process by using the verify command. Command VERIFY Description Verifies the integrity of the data between the source and target machines.
Setting the verification log attributes 1. To determine the current status of the verification log, use the get command with the VerifyLogName option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Examples Notes ! set netport=1100 ! set VerifyLogName=”HA server.log” ! set DefaultAddress=”129.12.34.3” ! Some settings, although immediately applied to Storage Mirroring, will not take effect until the client or service is restarted. For example, the Text Client must be closed and reopened for a change to ClientLogName to take effect. And the service must be restarted to cause a change in the modules loaded if the LoadSourceTarget setting is changed.
10 ! Data Transmission Data Transmission Storage Mirroring’s replication and mirroring processes place replication set data on queues on the source and the transmission process sends the data from the source to the target. There are three methods for transmitting the Storage Mirroring data: ! Real-time transmission—Storage Mirroring data is continuously transmitted to the target machine.
Scheduled Transmission Options The following transmission options are available through the Management Console and the Text Clients. They are user configurable settings which can occur in any order or combination. The options can be set and then disabled, allowing you to enable them only when you need to use them. NOTE: ! The transmission options are set for each target machine and cannot be defined separately for each replication set or source/target combination.
! Setting a Storage Mirroring Transmission Window—The transmission window establishes a period of availability for all Storage Mirroring transmissions. You can specify a begin and end time for all Storage Mirroring transmissions. When a transmission window is in effect, all other start and stop criteria are bound by this window. This means that Storage Mirroring will never transmit data outside of an established window, regardless of other transmission settings.
Setting bandwidth limitations 1. Select the Bandwidth option in the Limit Type box. 2. Mark the Limit Bandwidth check box to enable the bandwidth limiting features. 3. Define the bandwidth available for Storage Mirroring transmission ! Connection Speed—Specify the total bandwidth capacity that is available ! Percentage—Specify the percentage of bandwidth to be used for Storage Mirroring transmissions The Transfer Rate will automatically be calculated. 4.
Setting transmission start criteria Transmission start criteria initiates Storage Mirroring data transmission which continues until the queue is empty or a transmission stop criteria is met. 1. Select the Start option in the Limit Type box. 2. Define the start options for Storage Mirroring transmission by using any combination of the following options: ! Transmission session start—Specify a Date and Time to start transmitting data.
Setting transmission stop criteria Transmission stop criteria stops Storage Mirroring data transmission after a transmission start criteria has initiated the transmission. If a stop criteria has not been established, the transmission will end when the queue is empty. 1. Select the Stop option in the Limit Type box. 2.
Setting a transmission window The transmission window establishes a period of availability for all Storage Mirroring transmissions. NOTE: Setting a transmission window by itself is not sufficient to start a transmission. You still need to set a start criteria. 1. Select the Window option in the Limit Type box. 2. Mark the Enable Transmission Window check box to enable the transmission window feature. 3.
Controlling transmission manually To start, stop, pause, or resume the transmission of data from the source to the target, right-click an established connection and select Transmit and the appropriate transmission control.
Setting Transmission Criteria Using the Text Client The Text Client uses the schedule commands to establish scheduled transmission criteria. To control transmission manually using the Text Client, the transmission command can be used with the stop, start, pause, or resume switches. Configuring transmission criteria before establishing a connection After you have specified the source you are working with, establish scheduled transmission criteria using the following various schedule commands.
Setting bandwidth limitations Set the bandwidth by using the limit bandwidth command.
Setting transmission stop criteria Specify any of the following options to stop transmitting Storage Mirroring data to the target machine. ! Specifying Transmission Duration—Specify the maximum length of time that Storage Mirroring can continue transmitting by using the schedule end command with the duration switch.
Transmission schedule examples This section shows examples of how the different schedule commands could be used together. NOTE: ! The numbers and times were randomly selected for these examples. Be sure to use values that work for your environment. Example 1—In this example, transmission is set to begin on January 12, 2003, at 10:30 p.m. and to end after 6 hours.
Controlling transmission manually To start, stop, pause, or resume the transmission of data from the source to the target, use the transmission command with the start, stop, pause, or resume switches. ! ! ! ! To start the transmission process, use the transmission start command.
Pausing Storage Mirroring Execution on the Target Storage Mirroring servers running version 4.2 or later can pause the execution of operations on the target, even if there are no active connections to that target. For targets that do have active connections, any operations already in progress are completed, while any new incoming operations are queued until execution on the target is resumed, at which time the queued operations are processed.
Resuming through the Management Console Use either of the following methods, to resume execution on the target: ! Right-click on the left pane of the Management Console, on a target server which you are logged in to, and select Resume Target. ! Right-click on a connection in the Target tab on the right pane of the Management Console and select Resume Target. If you have an established connection, verify in the Target Status field that the target is resumed.
11 ! Failover Failover Failover is a component of Storage Mirroring that allows a target to stand in for a failed source machine. The failover target assumes the network identity of the failed source. When the target assumes the identity of the source, user and application requests destined for the source machine or its IP address(es) are routed to the target.
Failover Clients ! Management Console—Failover processing is integrated in the Management Console Connection Manager allowing you to: ! ! ! Configure both monitoring and failover options when establishing a connection for mirroring and replication ! Configure failover for any operating system Text Client—Failover processing is integrated in DTCL allowing you to: ! Configure both monitoring and failover options from any of the Storage Mirroring text clients ! Configure failover for any operating
How Failover Works 1. The target machine monitors the source machine and waits for a failure. Monitor Requests and Replies Source Name: Marketing IP Address: 125.7.82.43 Target Name: Backup IP Address: 125.7.82.67 User and application requests are sent to the source by locating the IP address 2. A source failure is detected and the failover process begins. (For more information on failure detection, see How Failure Detection Works on page 11-5.) 3.
5. Source shares are created on the target allowing shared resources on the source to be accessible on the target machine. Any drives shares that existed on the target prior to failover are stored so that they can be reestablished after failback. NOTE: When replicating data using Storage Mirroring, only shares that are within the Storage Mirroring replication set will be created on the target machine during the failover process. Shares outside of the replication set will not be created on the target. 6.
How Failure Detection Works 1. The target sends a monitor request, which is an ICMP ping, to each monitored IP address at a user-defined interval. A monitor reply is sent from the source back to the target. 2. When the user-defined number of missed packets is met, the address is considered failed.
Windows NT 4.0 ! Storage Mirroring failover can monitor an unlimited number of source machines (limited only by the number of IP address placeholders that exist) and can assume the identity of multiple sources. ! During the failover process, by default, the target can maintain its original identity and add the name(s) and IP address(es) of one or more failed source machines. ! The target can optionally be configured to replace its original identity with that of the source machine.
Failover Hardware Configurations Failover can be configured to stand in for one or more IP addresses associated with different NICs on the source. Each IP address can be added to a specific target NIC making NIC configuration very flexible. Following are some sample configurations. NOTE: If a failover target is monitoring a source for failure and a new NIC is added to the target server, you will need to reinstall Storage Mirroring to properly setup the new NIC for failover placeholders.
Multiple NICs on the source and target With any source configuration, additional NICs on the target increases flexibility and control. Secondary target NICs can assume the traffic from a failed source NIC while normal target traffic can continue to use the primary target NIC. Multiple sources can be directed to specific NICs. For example, a single target containing three NICs monitors three source machines located on different subnets. Each source has one NIC attached to a different subnet.
Failover Options In order for failover to stand in for a failed machine, you must configure the monitoring and failover options. These options are the same regardless of the configuration method (Management Console, Failover Control Center, or Text Client) that you use. ! Source Machine—The machine that is monitored for failure. ! IP Addresses—The machine that is monitored for failure may have one or more IP addresses.
Managing Failover Through the Management Console 1. After you have configured a source/target connection by following the steps in Establishing a new connection on page 6-7, you can configure failover by selecting the Failover tab from the Connection Manager. 2. The Failover tab will display the source machine IP addresses that are available for monitoring. 3. To enable monitoring between this source and target, select the Enable Monitoring check box. 4.
11. If you are monitoring multiple IP addresses, specify Trigger Condition. ! All Monitored Addresses Fail—Failover begins when all monitored IP addresses fail. ! Any Monitored Address Fails—Failover begins when any of the monitored IP addresses fails. 12. If you are monitoring multiple IP addresses, specify Addresses to Failover. ! Monitored Addresses—Failover is only performed on the monitored IP addresses. ! All Addresses—Failover is performed on the monitored and unmonitored IP addresses. 13.
Managing Failover Through the Failover Control Center Through the Failover Control Center, you can configure and monitor the failover process. The failover settings determine what users experience during a failover. In addition, the Failover Control Center can be used to initiate the failback process and to offer additional options. Configuring monitoring and failover 1. The Failover Control Center can be started from within the Management Console or from the Windows desktop.
5. 6. Specify your source machine by any of the following methods: ! Type the name of the machine that you want to monitor in Machine Name(s) and click OK. You can enter multiple names if you want to monitor more than one machine by separating the names with a space. ! Click Custom, specify the IP address (with or without a port number) of the machine you want to monitor, click OK. ! Click Browse to search for a machine.
! Failover Processing—Failover Trigger, Failover Method, and Items to Failover ! Miscellaneous Source Machine Options—Manual Intervention, Use .SHR Share Mapping File, and Active Directory NOTE: The target machine is identified in the Monitor Settings dialog box title bar. All changes made in this dialog box are for the machine referenced in the title bar. If the wrong target is selected, close the Monitor Settings dialog box and select a different target from the Failover Control Center window. 7.
! Shares—Failover is performed on shares. NOTE: Share information is automatically updated on the target once an hour. If you need to manually update the share information, click Update Shares on the main Failover Control Center window after the connection has been established. If a share is created on Windows NT 4 or Windows 2000 with the default full access permissions (without an ACL) and then failed over, the permissions given to the target will be dependent on the target's operating system.
19. If you are using any scripts, click Scripts and enter the path and filename for each script type. NOTE: If you click Browse next to the Source Post-Failback script, the directory structure for the target machine appears by default. From this point, you can access your network so that you can see the directory structure for the source machine, and then select the file you want. 20.
Monitoring failover Now that replication and failover monitoring are configured and started, you will need to know if and when there is a problem. Since it can be essential to quickly know the status of your machines, Storage Mirroring offers various methods for monitoring the status of failover.
The following table identifies how the visual indicators change as the status of failover changes. Time to Fail Countdown Source is Online Source Fails and Failover is Initiated Failover is Complete Status Bar Colored Bullets Desktop Icon Tray The Time to Fail counter is counting down and resetting each time a heartbeat is received from the source machine. The status bar indicates that the target machine is monitoring the source machine. The bullets are green.
4. Select the failed source and click Failback. If you specified a pre-failback script in your failover configuration, that script will be executed at this time. 5. You will be prompted to determine if you want to continue monitoring the source. Bring the source online and select Continue or Stop to indicate if you want to continue monitoring the source. After you have selected whether or not to continue monitoring the source machine, the source post-failback script, if configured, will be started.
Failover IP address placeholders For Windows NT 4.0, IP address placeholders exist so that during the failover process, the source’s IP address can be assumed by the target without requiring a target machine reboot. The number of placeholders defined must be the maximum number of IP addresses for which the target adapter will need to respond. If all of the defined placeholders have been replaced due to failovers, the target cannot assume or respond for any additional IP addresses.
Communication ports The Storage Mirroring service and the Failover Control Center use two ports for various Storage Mirroring communications. ! ! Service Transmit Port—The Failover Control Center uses this port to send commands to Storage Mirroring servers. Heartbeat Listen Port—The Failover Control Center uses this port to listen for heartbeats transmitted from Storage Mirroring servers. To view or modify the port settings in the Failover Control Center, select Settings, Communications.
Testing failover The failover process, including pre-failover and post-failover script processing, can be tested at any time. To force unavailability, disconnect the network cable from a monitored machine, wait for the Time to Fail counter to decrease to zero and failover begins. To avoid the countdown delay, highlight the monitored machine name in the Failover Control Center window and select Failover. NOTE: Remove the source from the network before testing failover.
Managing Failover Through the Text Client Through the Failover Control Center, the failover process can be configured, monitored, and tested. In addition, the Failover Control Center can be used to initiate the failback process. Configuring monitoring and failover 1. If you are using Storage Mirroring replication, establish a source/target connection by following the steps in Establishing a new connection on page 6-13. 2. Specify a target machine by using the target command. 3. 4.
5. 6. Specify that you want to use the monitor that was just created by using the monitor use command.
7. To remove an IP address from an established monitor, use the monitor remove command. Command MONITOR REMOVE Description Removes an IP address that is currently being monitored Syntax MONITOR REMOVE [monitor] Options ! IP_address—The currently monitored IP address that should be removed ! monitor—Name of the source machine designated as the monitor ! monitor remove 205.31.2.57 indy monitor remove 205.31.2.68 Examples ! Notes 8.
Examples ! ! Notes monitor option monitor option nomovename The default settings are movename, moveaddress, moveshares, add, usesharefile, failall, fodelay, fbdelay, and intervention. Storage Mirroring version 4.
10. Remove any scripts by using the monitor script remove command.
Storage Mirroring version 4.3 Source Machine: indy (Access Level: FULL) - Monitor settings for indy Flags: ADD, USESHAREFILE, FAILALL Target Pre-Failover script:c:\scripts\preover.txt Target Post-Failover script:c:\scripts\postover.txt Target Pre-Failback script:c:\scripts\preback.txt Target Post-Failback script:c:\scripts\postback.txt Source Post-Failback script:c:\scripts\src_postback.txt (press any key) > > > > monitor monitor monitor monitor script add prefailback c:\scripts\preback.
14. If you need to clear the monitor settings so that they can be reconfigured, use the monitor clear command. Command MONITOR CLEAR Description Clears all of the failover configuration and monitoring parameters for the specified monitor machine Syntax MONITOR CLEAR [monitor] Options monitor—Name of the source machine designated as the monitor Examples monitor clear indy Notes If you do not specify a monitor, the current source designated as the monitor will be used.
Initiating failback When failover occurs, a source machine has failed. The steps below must be completed in order to complete failback without IP address or name conflicts. 1. Verify the source machine is not connected to the network. If it is, disconnect it. 2. Resolve the source machine problem that caused the failure. WARNING: Do not connect the source machine to the network at this time. 3. 4. 5.
12 ! Restoration Restoration The Storage Mirroring restoration process provides an easy method for copying replicated data from the target back to its original location on the source. The process only requires you to select the source, target, and the appropriate replication set. There is no need to select files or to remember where the data came from on the source since that information is maintained by Storage Mirroring.
How the Restoration Process Works 2 3 3 5 Replication Set Replication Set Backup 6 1 Source 4 Target File Conditionals 1. The network administrator resolves the source machine problems and in the process reinstalls Storage Mirroring, if necessary. 2. The network administrator initiates restoration through one of the Storage Mirroring clients. 3.
Restoration Options When restoring Storage Mirroring data, you must specify the source and target machines and the replication set from the source machine that contains the data that was lost and needs to be restored, as well as configure how the restoration process will occur.
Restoration Conditional Options Only if Backup Block Checksum is Overwrite Files All Server Newer Restoration Properties Restoration Option Source Taba Option Block Checksum Restoration Option Action Performed (! ) If no restoration options are selected, only the files that exist on the target but not on the source will be transmitted to the source. (! ) ! All files on the target are restored to the source. The restoration sends the entire file.
Restoring Storage Mirroring Data Through the Management Console 1. From the Management Console, select Tools, Restoration Manager. 2. Select the Original Source machine. This is your source machine where the data originally resided. 3. Select the Restore From machine. This is the target machine where the backup data is stored. 4. Replication Set contains the replication set information stored on the target machine (the machine in Restore From).
7. Select the Use Backup Replication Set check box to use the backup of the replication set stored on the target machine for the restore. If this check box is not marked, you will be accessing the replication set from the source machine. 8. Select the Restore Replication Set check box to restore the target’s backup of the replication set database to the source machine during the restore process. 9. Select the restoration conditionals that you want to use.
Restoring Storage Mirroring Data Through the Text Client 1. Log on to your source machine using the login command. Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options ! machine—Name of the machine ! username—Name of the user ! password—Password associated with username. ! domain—If logging in using a domain account, this is the domain name. If logging in using a local account, this is the machine name.
4. Restore Storage Mirroring data from target to the source by using the restore from command.
Automating Restore You can use a post-failback script on the source to automate the restore process. For example, the following two files automate the restore process. In your failover configuration, identify spostback.bat as your post-failback script on the source machine. This batch file calls the second script below, spostback.txt, which automates the restoration. SPOSTBACK.BAT cd c:\Program Files\OpenView\Storage Mirroring cmd /c DTCL -f "c:\Program Files\OpenView\Storage Mirroring\spostback.
SPOSTBACK.TXT # # # # # # # # # # # # SAMPLE SOURCE FAILBACK AND RESTORE SCRIPT THIS POST-FAILBACK SCRIPT EXECUTES ON THE SOURCE. THIS SCRIPT PERFORMS A TARGET-SOURCE RESTORE AND REESTABLISHES THE CONNECTION AND STARTS MIRRORING.
SPOSTBACK.TXT (continued) # Restore target data to source before # recreating original connection # Restore ID should be 1 or greater, so exit on failure $restID=RESTORE from original overwrite; if $restID < 1 then WRITE “restore failed from ”; WRITE $restID; quit; end SOURCE ; WAITONRESTORE $restID; # Add a hard wait of 20 seconds to clear queues.
13 ! Monitoring Tools Monitoring Tools Storage Mirroring offers a variety of tools for monitoring Storage Mirroring activity. With these monitoring tools, you can obtain the status of Storage Mirroring machines, connection statistics, and alerts. Alerts are processing notifications, warnings, and/or errors. ! ! Management Console Tools ! The Management Console main window displays source/target connection and statistical information in the right pane.
Management Console Tools The Management Console tools include: ! The Management Console main window which displays source/target connection and statistical information in the right pane. ! At-a-glance monitoring includes icons and graphics that indicate the status of Storage Mirroring machines and connections. ! The Message Window displays alert messages.
Statistic Mirror Status Replication Status Description ! Percentage Complete—If the file size of the replication set has been calculated and the data is being mirrored to the target machine, the Mirror Status will display the percentage of the replication set that has been sent. ! Waiting—Mirroring ! Restoring—Data is being restored from the target to the source. ! Verifying—Data is being verified.
Customizing the statistics You can change the statistics that are displayed on the Management Console main window by following these steps: 1. Select File, Options and click the Statistics tab. The statistics will be listed with check boxes to the left of each item. 2. Mark the check box to the left of each statistic that you want to appear on the Management Console main window. 3. Clear the check box to the left of each statistic that you do not want to appear on the Management Console main window.
At-a-Glance monitoring At-a-glance monitoring includes icons and colors that indicate the status of Storage Mirroring machines and connections. Each icon or color that indicates the status of Storage Mirroring activity is described in the following tables. ! The icons in the left pane indicate what modules are loaded on each machine. Left Pane Icons Icon Description The world icon is selected. The Storage Mirroring machines are displayed in the right pane of the Management Console.
! The right pane displays the following information depending on the item selected in the left pane of the Management Console and the tab selected on the right pane. Right Pane Icons Left Pane Right Pane Description World View No Tabs All connected machines and their current connection state are displayed. Source Machine Source Tab The active connections, if any, from that source machine are displayed. Source Machine Target Tab The display is blank.
! The following table identifies the different icons and colors that you may see in the right pane of the Management Console when you have a machine with an established connection selected. These icons let you know, at-a-glance, the status of your Storage Mirroring connections. Connection Icons Icons and Colors Description A green checkmark appears in the right pane of the Management Console to the left of the connection data line for an established connection that is working properly.
Customizing when the background color and icons change Communications between the Management Console and the source are monitored by requests and responses. The Management Console sends a request to the source and expects a response back. If the Management Console exceeds the number of responses that can be missed, the Management Console changes icons and color to alert you to potential problems.
Management Console message window The Management Console message window displays Storage Mirroring processing alerts. These alerts include notifications, warnings, and errors. Use the instructions below to create and control the Management Console message window. NOTE: The standard appearance of the message window is a white background. If your message window has a gray background, the window is inactive.
2. To control the window after it is created, use either of the following methods to access the control methods listed in the table: ! Right-click on the message window and select the appropriate control. ! Select the appropriate toolbar control ! Select Monitor, the name of the message window, and the appropriate control. Message Window Control Description Close Closes the message window Clear Clears the message window Pause/ Resume Pauses and resumes the message window.
Text Client Tools The text client tools include: ! The Text Client main window which displays source/target connection and statistical information ! DTCL status command which displays connection and status information Text Client main window After a source/target connection is established, the Text Client main window displays basic connection and statistical information for the active source machine. NOTE: Use the source command to set a machine as the active source.
DTCL status command Use the status command to display statistical and informational data.
Operating System Dependent Tools The operating system dependent tools include: ! Windows Event Viewer ! Windows Performance Monitor Windows Event Viewer In the Windows operating system, an event is a significant occurrence in the system or in an application that requires administrators to be notified. The operating system writes notifications for these events to a log file that can be displayed using the Windows Event Viewer.
Event descriptions The following table identifies the events generated by Storage Mirroring. Category ActivationKey ID Severity Message Required Response 1 Error This evaluation period has expired. Mirroring and replication have been stopped. To obtain a license, please contact your vendor. Contact your vendor to purchase either a single or site license. 2 Info The evaluation period expires in %1 day(s).
Category DblTake DTCounters ID Severity Message Required Response 16387 Info A FILE_OBJECT collision was detected No action required. and managed. This message is for informational purposes only and does not indicate a problem. 16388 Info Unable to buffer for name of replication pagefile. Replication is not affected. The paging of replication ops is disabled. 16389 Info Unable to create a pagefile for replication. The Storage Mirroring driver could not Replication is not affected.
Category DTCounters Failback Failover Monitoring NSIPHDriver ID Severity Message Required Response 1004 Error The Double-Take counter DLL could not Run the Storage Mirroring installation and read the "First Counter" value under the select Repair. Contact technical support if Double-Take\Performance Key. this event occurs again. 1005 Error The Double-Take counter DLL read the "First Help" value under the Double-Take\Performance Key.
Category ID Severity Message Required Response NSIPHDriver 9002 Error Could not allocate memory for parameter key Reboot the server and contact technical support if this event occurs again. 9003 Error Could not read PlaceHolderCount from the NSIPH Parameters key Reboot the server and contact technical support if this event occurs again. 9004 Error Could not allocate buffer to hold initial IP Reboot the server and contact technical address list for adapter support if this event occurs again.
Category Resources Service ID Severity Message Required Response 8200 Warning Failed to allocate buffer for querying very Reboot the server and contact technical long filenames, i.e., names over 260 support if this event occurs again. characters. Replication will continue for standard length filenames. The last Word in the Data Window is the NT status code. 8201 Warning Reached stop replicating page limit. Replication is stopped.
Category Service ID Severity Message Required Response 4019 Info Service has started a mirror to %1 for Replication Set %2, ID: %3 No action required. 4020 Info Service has paused a mirror for ID: %1 No action required. 4021 Info Service has resumed a mirror for ID: %1 No action required. 4022 Info Service has stopped a mirror for ID: %1 4023 Success Service has completed a mirror for ID: %1 No action required. 4024 Info Service has started Replication, ID: %1 No action required.
Category Service ID Severity Message Required Response 4037 Error Error verifying the vendor URL name. The product functionality has been disabled. Reinstall the software, using the installation Repair option, to install a new copy of the RSResource.dll. Contact technical support if this error persists. 4038 Error Error verifying the product code. The product functionality has been disabled. Reinstall the software, using the installation Repair option, to install a new copy of the RSResource.
Category Service ID Severity Message Required Response The operation has been retried according to the TGExecutionRetryLimit setting but was not able to be written to the target and the operation was discarded. Correct the problem and remirror the files. 4150 Error Target write %1 failed after %2 retries and will be discarded. See the event log or log files for error conditions. After correcting the problem, you should re-mirror or run a verify to resynchronize the changes.
Category Service System ID Severity Message Required Response 10004 Warning Failover of the group %1 is being delayed. No action required. Group will be brought online when the target queue is below the limit or the timeout has expired. 10005 Info Node %1 is taking ownership of the group No action required. %2. The group will be brought online on this node. 4096 Warning Unknown registry parameter specified. Parameter is named "%2." 4097 Error Failed to load nsi-filter.
Windows Performance Monitor Performance Monitor is a graphical tool for measuring the performance of your own computer or other computers on the network. It provides charting, alerting, and reporting capabilities that reflect both current activity and ongoing logging. You can open, browse, and chart log files later as if they reflected current activity. Storage Mirroring statistics are available through the Performance Monitor. 1.
Performance Monitor statistics Object Connection Kernel Statistic Description Bytes in disk queue The number of bytes in the source disk queue Bytes in replication queue The number of replication bytes in the source queue Bytes in mirror queue The number of mirror bytes in the source queue Bytes received The number of bytes received by the target since the last Performance Monitor refresh Bytes transmitted The number of bytes transmitted from the source Operations in acknow- ledgement queue T
Object Security Source Target a Statistic Description Failed logins Number of failed login attempts since the last time the Storage Mirroring service was restarted Successful logins Number of successful login attempts since the last time the Storage Mirroring service was restarted Auto disconnects The number of automatic disconnects since the last time the Storage Mirroring service was restarted on the source Auto reconnects The number of automatic reconnects since the last time the Storage Mirr
Operating System Independent Tools The operating system independent tools include: ! DTStat ! LogViewer ! SNMP DTStat Statistics logging is the process of taking snapshots of Storage Mirroring statistical data and writing it to a file for future use. Statistics are automatically gathered and written to disk by the Storage Mirroring service.
Modifying the log file settings through the Management Console 1. Right-click a machine in the left pane of the Management Console and select Properties. 2. Select the Logging tab. 3. At the top of the tab, specify the Folder where the log files for messages, alerts, verification, and statistics will be saved. 4. Under Statistics, specify the following information: 5. ! Filename—The name of the statistics log file. The default file name is statistic.sts.
Modifying the log file settings through the text clients 1. To determine the current location where the log file is stored, use the get command with the StatsFileName option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Running DTStat You can run DTStat from the Storage Mirroring Text Client or from any command prompt. Running DTStat from the text clients To determine the status of DTStat or to stop or start it through the Text Client, use the statslog status, statslog start, or statslog stop commands. ! ! ! Starting DTStat Command STATSLOG START Description Starts the DTStats statistics logging utility.
Running DTStat from the command prompt From a command prompt, use the DTStat command from the location where Storage Mirroring is installed. Command DTSTAT Description Starts the DTStats statistics logging utility from a command prompt.
DTStat statistics The following statistics appear in the statistic.sts file. If you convert that file to an ASCII, comma-delimited file using the dtstat -s option, the heading labels may appear slightly different. Category Statistic Description Date/Time Stamp The date and time that the snapshot was taken. This is the date and time that each statistic was logged. By default, these are generated once a second, as long as there are statistics being generated.
Category Target a Source Connection Statistic Description Peer Address The IP address of the source machine Ops Received The total number of operations received by this machine as a target since the Storage Mirroring service was loaded MirrorOps Received The total number of mirror operations received by this machine as a target since the Storage Mirroring service was loaded. This number does not reset to zero for remirrors.
Category Connection Statistic conState Description The state of the active connection 0—Error. This indicates a connection that is not transmitting because something has gone wrong (for example, lost connection). 1—Active. This indicates that the connection is functioning normally and has no scheduling restrictions imposed on it at this time. (There may be restrictions, but it is currently in a state that allows it to transmit.) 2—Paused. This indicates a connection that has been paused. 3—Scheduled.
Category Connection Statistic Description conTask Cmds Submitted The number of task commands that have been submitted on the source conTask Cmds Queued The number of task commands that have been queued on the source conTasks Succeeded The number of task commands that have succeeded on the source conTasks Failed The number of task commands that have failed on the source conTasks Ignored The number of task commands that have been ignored on the source a.
LogViewer LogViewer is a utility that gathers Storage Mirroring alerts. These alerts, which are proccessing notifications, warnings, and error messages, are written to disk and can be displayed using the LogViewer. Sample LogViewer Output 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 01/15/2003 14:14:18.3900 14:14:18.4200 14:14:18.5350 14:14:18.6760 14:14:18.9870 14:24:15.2070 14:24:16.3090 14:24:40.9680 14:25:22.4070 14:25:22.
LogViewer log file Each log file consists of a base name, a series number, and an extension. ! Base Name—The base name is determined by the application or process that is running: Component ! Log File Base Name Storage Mirroring dtlog Management Console mc Failover Control Center fcc Text Client dttxt Command Line Client dtcl Series Number—The series number ranges from 1 to 999. For example, Storage Mirroring begins logging messages to dtlog1.
Modifying the log file settings through the Text Client 1. To determine the current location where the log file is stored, use the get command with the LogDir option. Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Viewing the log files Use the LogViewer command from the directory where Storage Mirroring is installed to view a Storage Mirroring log file. Command LOGVIEWER Description The Storage Mirroring logging utility that records alerts (processing notifications, warnings, and errors) that occur during Storage Mirroring processing.
LogViewer Messages The following table describes the standard Storage Mirroring alerts that may be displayed in the LogViewer. The ID appears in column 7 of the LogViewer, and the message appears in column 8 of the LogViewer. In the following table, con_id refers to the unique connection ID assigned to each connection between a source replication set and a target. NOTE: ID Message Description 0 N/A There are several log messages with this ID#.
ID Message Description 79 Memory freed to bring Storage Mirroring memory usage below the limit Data in the source queue has been sent to the target machine, bringing the pagefile below its limit. 80 Trying to auto-retransmit to ip://xxx.xxx.xxx.xxx Storage Mirroring is attempting to automatically reconnect previously established source and target connections after a server reboot or auto-disconnect. This is also referred to as the auto-reconnect process.
ID Message Description 102 Target full! 801 Auto-disconnect has occurred on IP address Auto-disconnect has occurred for the specified connection. This address with connection con_id Disconnected is due to the source queue filling up because of a network or replication set name: repset_name. target failure or bottleneck. 10001 Activation key is not valid. An invalid activation code was identified when the Storage Mirroring service was started. 10002 Evaluation period has expired.
ID Message Description 53003 Could not read filename Storage Mirroring could not read a file on the source machine because the file may have been renamed or deleted. For example, temporary files show up in queue but do not show up during transmission. (No user action required.) 54000 Kernel started The Storage Mirroring service was started. 54001 Failover module failed to load The Storage Mirroring failover module failed to load. Look at previous log messages to determine the reason.
SNMP SNMP, Simple Network Management Protocol, is the Internet's standard for remote monitoring and management of hosts, routers and other nodes and devices on a network. Storage Mirroring provides an SNMP sub-agent that monitors Storage Mirroring and can be managed from an SNMP Management Console. Storage Mirroring installs two components to work with SNMP: ! The sub-agent is a program that installs and runs on the same machine as Storage Mirroring and gathers statistics, data, and traps.
Source Statistic Description DtconOpsInAckQueue The number of operations (create, modify, or delete) waiting for verification acknowledgements from the target DtconOpsInCmdQueue The number of operations (create, modify, or delete) in the retransmit queue on the source DtSourceState 0—Source is not running 1—Source is running without the replication driver 2—Source is running with the replication driver. Target Statistic Description DtconIpAddress The IP address of the connected machine.
Connection Statistic Description DtAutoDisCount The number of auto-disconnects DtAutoReCount The number of auto-reconnects DtconBytesRx The total number of bytes received from the target DtconBytesTx The total number of bytes transmitted to the target DtconConnectTime The duration of time since the connection was first established DtConnectionCount The number of active connections between machines DtconOpsRx The total number of operations (create, modify, or delete) received from the target
SNMP traps The following tables identify the Storage Mirroring traps provided through SNMP.
Replication Trap Description DttrapReplicationStart Replication has started DttrapReplicationStop Replication has stopped DttrapRepSetModified Replication has been modified Connection Trap Description DttrapAutoDisconnect EndConnection Auto-disconnect has intentionally dropped the connection DttrapAutoDisconnect PauseTransmission Auto-disconnect requested that the source pause any operation (create, modify, or delete) sending DttrapAutoDisconnect Auto-disconnect forced Storage Mirroring to sh
Verification Trap Description DttrapVerificationEnd Verification has ended DttrapVerification Failure Verification has failed DttrapVerificationStart Verification has started Failover Trap Description DttrapFailover ConditionMet Manual intervention is required because failover has detected a failed source machine DttrapFailoverIn Progress Failover is occurring Restoration Trap Description DttrapRestore Complete Restoration is complete DttrapRestoreStarted Restoration has started 13 - 48
14 ! Advanced Settings Advanced Settings The Storage Mirroring program settings are the user-definable options that control Storage Mirroring application settings and Storage Mirroring processing settings. This includes options like the name of the verification log file and the size of the Storage Mirroring memory pool. Changing the Settings Through the Management Console All of the Storage Mirroring server settings are located in the Server Properties dialog box.
General options The General tab contains basic settings for the selected machine including the machine’s identity and its Storage Mirroring functionality. ! Nickname—You can specify a machine nickname which is saved in the Management Console workspace. This nickname will only appear on the Management Console on this machine. It is not communicated across the network, but if this workspace is used on another machine, it will also appear there.
Setup options The Setup tab consists of settings that are initialized when Storage Mirroring is started. ! Log Statistics Automatically—This check box indicates whether Storage Mirroring statistics logging, which logs to the statistic.sts file, will start when Storage Mirroring is started. For detailed information on the Storage Mirroring statistics logging, see DTStat on page 13-26. ! Enable Task Command Processing—This check box indicates whether task command can be processed on this server.
Network options The Network tab consists of settings that control network communications. Any changes made to this tab will not take effect until the Storage Mirroring service has been restarted on the specified machine. ! Interface ! Default Address—On a machine with multiple NICs, you can specify which address Storage Mirroring traffic will use. It can also be used on machines with multiple IP addresses on a single NIC.
Queue options The Queue tab consists of settings for Storage Mirroring queue usage. Folder—This is where the queue will be stored. For best results and reliability, you should select a dedicated, non-boot volume. Maximum system memory for queue—This is the amount of Windows system memory that, when exceeded, will Maximum disk space for queue—This is the maximum amount of disk space in the specified Folder that can be used for trigger queuing to disk. Storage Mirroring queuing.
Source options The Source tab consists of settings specific to the source module of Storage Mirroring. ! Replication Packets to 1 Mirror Packet—This option allows you to specify the ratio of replication packets to mirror packets that are placed in the source queue. Specify a larger number if you have a busy network that has heavy replication. Also, if you anticipate increased network activity during a mirror, increase this number so that the replication queue does not get too large.
Target options The Target tab consists of settings specific to the target module of Storage Mirroring. ! Target Mirror Capacity High Percentage—This option specifies the maximum percentage of Windows system memory that can contain mirror data before the target signals the source to pause the sending of mirror operations. The default setting is 20.
Database options The Database tab consists of settings that specify the name and location for the database files used by Storage Mirroring processes. ! Folder—Specify the directory where each of the log files on this tab are stored. The default is the directory where the Storage Mirroring program files are installed. ! Replication Set—This database file maintains which replication sets have been created on that machine along with their names, rules, and so on. The default file name is DblTake.db.
Logging options The Logging tab consists of settings for various log files. ! Folder—Specify the directory where each of the log files on this tab are stored. The default is the directory where the Storage Mirroring program files are installed. ! Messages & Alerts ! Maximum Length—Specify the maximum length of the Storage Mirroring alert log file. The default size is 1048576 bytes and is limited by the available hard drive space.
Changing the Settings Through the Text Client Changing Storage Mirroring settings using the Text Client can be confusing because the settings for a Storage Mirroring source or target are stored in the same location as the settings for the Storage Mirroring Text Client. Therefore, if you are running a Storage Mirroring source or target on the same machine that you are running the Text Client, and you update a client setting, you are also updating that setting on the source and/or target.
Storage Mirroring Text Client program settings The following table contains a complete listing of each Storage Mirroring program setting. Program Setting ActivationCode Description 16-character Storage Mirroring activation code Values: Found on registration card, if not an evaluation copy Default: n/a AdapterFlags Specifies the adapter to use when establishing a connection Values: (1) Compression (2) Encryption (4) Network Data Representation Default: 4 Compression is no longer used.
Program Setting AutoRemirrorRetry Description Specifies how often, in seconds, the source should check for connections that have been reconnected but still need to be remirrored Values: any integer Default: 30 AutoRetransmit Determines whether or not a source that has lost its connection with a target will attempt to reconnect to the target Values: (0) Do not attempt to reconnect (1) Attempt to reconnect Default: 1 BackupDir Location on the target of the backup of the replication sets Values: any valid
Program Setting ClientLog Description Indicates whether commands entered in the Text Client are tracked Values: (0) Not tracked (1) Tracked Default: 0 If you change this value, the Text Client must be closed and restarted to implement the change. ClientLogName Name of the log file that tracks commands entered in the Text Client Values: any valid file name Default: Dttext.log If the name of the log file is changed, the Text Client must be closed and restarted to start logging to the new log file.
Program Setting DropOpOnHandle Error Description Determines if an additional attempt is made to access a file by a Microsoft API call if the Storage Mirroring call fails.
Program Setting FailoverOnRoute Failure Description Determines if failover will occur when receiving a router message back from an IP address on the network Values: (0) Failover will not occur when receiving a destination host unreachable message (1) Failover will occur when receiving a destination host unreachable message Default: 1 FCCHelpPath The path and file name to the Failover Control Center online help file Default: c:\Program Files\OpenView\Storage Mirroring\online help\fcc\ wwhelp.
Program Setting HPQueueRatio Description Ratio of replication packets to one mirror packet Values: 0 - 65535 Default: 5 A HPQueueRatio of 5 indicates 5 replication packets to 1 mirror packet. If you change this value, the source service must be stopped and restarted to implement the change.
Program Setting LanguageSelected Description Specifies the language of the verification log Values: Depends on LanguagesSupported Default: Language used during the installation LanguagesSupported Specifies the available languages for the verification log. Do not modify this setting. If you need to add or remove language support, use the Storage Mirroring installation program.
Program Setting MaxDriverPagefile Size Description Specifies the amount of disk space, in MB, to use for Storage Mirroring driver paging Values: 64-4095 Default: 256 The Storage Mirroring driver pagefile is located in the directory specified by QJournalDir. MaxLogFileSize Maximum size, in bytes, of any .
Program Setting MirrorChunkSize Description Block size (in bytes) used in the mirroring process Values: 1 - 1048576 Default: 32768 (32K) A higher block size value gives you better throughput, but only to a certain point, then it starts using more memory (this has to do with the way memory is allocated and deallocated). A lower block size value produces slower throughput, but uses memory efficiently. The optimal value is 32768.
Program Setting NetworkRetry Description Specifies the interval, in seconds, at which Storage Mirroring will attempt to reconnect to the target Values: any positive number Default: 10 NetworkStatus Interval This entry is no longer used. NetworkTimeout The maximum length of time, in seconds, to wait on a network connection. If data is not received over a network connection within the specified time limit, the connection is closed.
Program Setting PriorityClass Description The priority level at which the service runs. Values: 2 Default: 2 ProductCode Used by the Storage Mirroring installation program to maintain the installation settings for an upgrade QJournalDir The location where the queue is stored. Values: any valid path Default: the location specified during the installation For best results and reliability, you should select a dedicated, non-boot volume. The queue should be stored on a fixed, local NTFS volume.
Program Setting Description RemoveOrphansTime Specifies the amount of time that must be expired before an orphan file is removed Values: 1 - 131072 minutes Default: 60 minutes RemoveSharesOn Disconnect Specifies if shares are removed on the target machine when a Storage Mirroring replication set is disconnected from a target or a source machine is manually shutdown by the administrator. (Shares are not removed if either the source or target machines fail.
Program Setting ShareFailover Description Specifies whether or not to failover shares Values: (0) Do not failover shares (1) Failover shares Default: 1 ShareUpdateInterval Specifies how often, in minutes, the share file will be sent to the target Values: 1 - 65535 Default: 60 SourcePendingAcks The number of operations received by the target queue in which the source is waiting for a response Values: 100 - 20,000 Default: 2000 SourcePostFailback Script Path on the source where the post-failback script
Program Setting StatsWriteInterval Description Interval, in minutes, in which statistics are written to the statistic.sts file Values: 0 - 65535 Default: 5 SystemMemoryLimit Set by the Storage mirroring service, each time it is started, to record the amount of available memory. TargetPaused Internal setting that indicates if the target machine is paused. Do not modify this setting. TargetPausedVirtual Internal setting that indicates which target machines are paused. Do not modify this setting.
Program Setting TGMirrorCapacity Low Description Minimum percentage of system memory that can contain mirror data before the target signals the source to resume the sending of mirror operations. Values: 1-75 Default: 15 The maximum value forTGMirrorCapacityLow is either 75 or TGMirrorCapacityHigh, which ever is lower. TGRetryLocked Minimum number of seconds to wait before retrying a failed operation on a target Values: 0-65536 Default: 3 TGThreadCount Number of threads actively writing files to disk.
Program Setting UseEventLog Description Specifies whether or not messages are logged to the Windows Event Viewer Values: (0) Do not log messages to the Event Viewer (1) Log messages to the Event Viewer Default: 1 UserIntervention Specifies whether or not user intervention is required to initiate a failover Values: (0) User intervention is not required (1) User intervention is required Default: 1 UseShareFile Specifies whether to create and use a share file or to use the shares that are currently stored
15 ! Security Security To ensure protection of your data, Storage Mirroring offers multi-level security using native operating system security features. Privileges are granted through membership in user groups defined on each machine running Storage Mirroring. To gain access to a particular Storage Mirroring source or target, the user must provide a valid operating system user name and password and the specified user name must be a member of one of the Storage Mirroring security groups.
How Storage Mirroring Security Works 1. When any Storage Mirroring client machine attempts to access a source or target machine running on Windows, it will attempt to automatically logon to the source or target using the three methods below. Source or target running on Windows that contains the security groups Logon...
Clearing Maintained Security Credentials By default, Storage Mirroring maintains cached security credentials on the client machine as described in How Storage Mirroring Security Works on page 15-2. To remove the credentials, follow these steps: 1. To access the credentials security option, click File, Options and select the Security tab. 2. To remove the security credentials, click Clear Cached Security Credentials. 3. Click OK.
Storage Mirroring Service By default, Storage Mirroring is configured to log on as the system account. If you want to select a specific account to run the service, use these instructions: 1. Open the Storage Mirroring service settings. ! Windows NT—Open the Control Panel Services applet and double-click the Storage Mirroring service. ! Windows 200x—Select Start, Programs, Administrative Tools, Services and double-click the Storage Mirroring service. 2.
Storage Mirroring Groups Storage Mirroring requires two local groups on each source and target for security. During the installation process, these groups are automatically created. The groups are assigned specific case-sensitive names: Double-Take Admin Double-Take Monitors The groups are installed differently depending on your operating system. ! Windows 200x—The local administrator and the domain administrator are automatically added to the Storage Mirroring Admin group.
Adding users to a group Users that need administrator access to Storage Mirroring must be added to the Double-Take Admin group. All users that need monitor only access must be added to the Double-Take Monitors group. In both cases, local users, domain users, or global groups may be added to the local groups. To add, delete, or modify users for a group, follow these steps: 1. Select Start, Programs, Administrative Tools (Common), and User Manager.
Windows 200x Active Directory Active Directory, a central component of Windows 200x, manages information about the resources in a networking environment. The Storage Mirroring service automatically registers with Active Directory when the service starts. Storage Mirroring servers on the network can be located by the Storage Mirroring heartbeats, by Active Directory, or both.
Configuring the Storage Mirroring service for Active Directory The Storage Mirroring service must have privileges to modify Active Directory, if you want to use Active Directory registration. There are two options for assigning the privileges. ! User account—Assign a user account to the Storage Mirroring service and assign the Active Directory privileges to that user. To assign the user account and the privileges, follow the steps outlined in Storage Mirroring Service on page 15-4.
A ! Storage Mirroring Commands Storage Mirroring Commands The Double-Take Command Language (DTCL) is a scripting language that can be used in either the Text Client or Command Line Client to manage and monitor Storage Mirroring components. It can also be used in script files to execute series and combinations of commands to meet specific needs.
Storage Mirroring Commands The Storage Mirroring commands are listed in alphabetical order on the following pages.
Connect Command CONNECT Description Establishes a connection between a replication set and a target machine Syntax CONNECT TO MAP EXACT | BASE | TO [,...
Connect TDU Command CONNECT TDU Description Establishes a connection between a replication set and the Throughput Diagnostics Utility to imitate a normal connection without transmitting any data across the network Syntax CONNECT TO TDU [connection flags] Options ! repset—Name of the replication set ! file_name—Name of the file to store the connection statistics generated by the TDU ! connection flags—The same options available in the standard connect command ! connect “Exc
DTStat Command DTSTAT Description Starts the DTStats statistics logging utility from a command prompt.
Environment Command ENVIRONMENT Description Displays a list of all Storage Mirroring machines available to the specified machine. Each machine is identified by machine name, IP addresses and whether or not the source and/or target modules are loaded. If no machine is specified, the information is provided for the machine currently specified as the source.
Get Command GET Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry. Syntax GET
Help Command HELP Description Displays the DTCL commands and their syntax Syntax HELP Notes ! Press any key to scroll through the list of commands. ! Press q to exit the help function. ! You can also type dtcl help from the directory where the Storage Mirroring program files are installed to display the DTCL commands and their syntax.
Login Command LOGIN Description Log on to a Storage Mirroring machine Syntax LOGIN [domain] Options ! machine—Name of the machine ! username—Name of the user ! password—Password associated with username. ! domain—If logging in using a domain account, this is the domain name. If logging in using a local account, this is the machine name.
LogViewer Command LOGVIEWER Description The Storage Mirroring logging utility that records alerts (processing notifications, warnings, and errors) that occur during Storage Mirroring processing.
Mirror Resume Command MIRROR RESUME Description Resumes a paused mirror Syntax MIRROR RESUME Options ! con_id—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs.
Mirror Stop Command MIRROR STOP Description Stops a paused mirror Syntax MIRROR STOP Options ! con_id—Connection ID assigned to the source/target connection ! *—Specifies all connection IDs ! mirror stop 1 mirror stop * Examples ! Monitor Clear Command MONITOR CLEAR Description Clears all of the failover configuration and monitoring parameters for the specified monitor machine Syntax MONITOR CLEAR [monitor] Options monitor—Name of the source machine designated as the monit
Monitor Display Command MONITOR DISPLAY Description Displays the monitoring and failover configuration settings for the specified monitor machine Syntax MONITOR DISPLAY Options monitor—Name of the source machine designated as the monitor Examples monitor display indy Notes If you do not specify a monitor, the current source designated as the monitor will be used. If you have not identified a monitor, you will receive an error message stating that a monitor has not been selected.
Monitor Move Command MONITOR MOVE Description Designates the IP address that will be failed over to the specified target NIC.
Monitor Option Command MONITOR OPTION Description Configures the settings to determine how failover will be performed Syntax MONITOR OPTION [MOVENAME | NOMOVENAME] [MOVEADDRESSES | NOMOVEADDRESSES] [MOVESHARES | NOMOVESHARES] [ADD | REPLACE] [, USESHAREFILE | NOUSESHAREFILE][, FAILONE | FAILALL] [, FODELAY | NOFODELAY] [, FBDELAY | NOFBDELAY] [, INTERVENTION | NOINTERVENTION] [monitor] Options ! MOVENAME—Moves the server name during failover ! NOMOVENAME—Does not move the server name during failov
Monitor Remove Command MONITOR REMOVE Description Removes an IP address that is currently being monitored Syntax MONITOR REMOVE [monitor] Options ! IP_address—The currently monitored IP address that should be removed ! monitor—Name of the source machine designated as the monitor ! monitor remove 205.31.2.57 indy monitor remove 205.31.2.68 Examples ! Notes If you do not specify a monitor, the current source designated as the monitor will be used.
Monitor Script Remove Command MONITOR SCRIPT REMOVE Description Specifies the scripts that should not be run during the failover and failback processes Syntax MONITOR SCRIPT REMOVE [monitor] Options ! type—Any of the following script types: ! PREFAILOVER—Specifies that the file is a pre-failover script to be run on the target before failover occurs ! POSTFAILOVER—Specifies that the file is a post-failover script to be run on the target after failover occurs ! PREFAILBACK—Specifies that t
Monitor Stop Command MONITOR STOP Description Stops monitoring the source machine for a failure Syntax MONITOR STOP [ON ] Options ! ! monitor—Name of the source machine designated as the monitor target_machine—Name of the target machine that will no longer be monitoring the source machine Examples monitor stop indy on jersey Monitor Use Command MONITOR USE Description Specifies the source machine designated as the monitor that will be used in subsequent monitor comman
Orphans Stop Command ORPHANS STOP Description Stops the process to remove orphan files on the target Syntax ORPHANS STOP con_id Options con_id—Connection ID assigned to the source/target connection Examples orphans stop 1 Pause Target Command PAUSETARGET Description Allows you to pause the execution of Storage Mirroring operations on the target Syntax PAUSETARGET [FROM ] Options ! target_machine—The name of the target machine where you want to pause executi
Queue Task Command QUEUETASK Description Queues tasks inline with replication data. Syntax QUEUETASK TO ONQUEUE = [args] | ONTRANSMIT = [args] | ONRECEIVE = [args] | ONEXECUTE = [args] [TIMEOUT = ] [INTERACT | NOINTERACT] Options ! job_name—Any name that you have assigned to the job. This will be the identifier you will see in the log files.
Notes ! The default setting for this command is nointeract. ! Any combination of one or more execution points can be used with the same queuetask command. ! All processing messages, including errors, can be viewed in the Storage Mirroring logs and the Windows Event Viewer. ! Onqueue will still execute as soon as the task is placed on the queue even if transmission is stopped (manually stopped or paused, unmet scheduled transmission criteria, etc.).
Repset Calculate Command REPSET CALCULATE Description Calculates the size of a replication set Syntax REPSET CALCULATE [repset] Options repset—Name of the replication set Examples ! Notes ! repset calculate marketing repset calc “Exchange repset” ! If a replication set name is not specified, the active replication set will be used. ! If the replication set name includes alpha-numeric characters, the name must be enclosed in quotation marks.
Repset Display Command REPSET DISPLAY Description Displays the rule of a replication set Syntax REPSET DISPLAY [repset] Options repset—Name of the replication set Examples ! Notes ! repset display repset display Exchange ! If you do not specify a replication set name, the current replication set will be used. ! If the replication set name includes non-alphanumeric characters, the name must be enclosed in quotation marks.
Repset Rule Add Command REPSET RULE ADD Description Adds a rule to a replication set. A rule is the specification of a path including volume, directories, wild cards, and/or file names.
Repset Save Command REPSET SAVE Description Saves all replication set rules for the currently selected source Syntax REPSET SAVE Repset Use Command REPSET USE Description Specifies a replication set as the active replication set Syntax REPSET USE Options repset—Name of the replication set Examples ! ! Notes repset use “Exchange Repset” repset use marketing_database If the replication set name includes non-alphanumeric characters, the name must be enclosed in quotation marks.
Restore Command RESTORE Description Initiates the restoration process Syntax RESTORE FROM [ORIGINAL ] [, OVERWRITE | NOOVERWRITE][, OVERWRITENEWER | NOOVERWRITENEWER] [, USETARGETDB | NOUSETARGETDB][, RESTOREDBTOO | NORESTOREDBTOO] [, CHECKSUM][, ORPHANS | NOORPHANS] Options repset—Name of the replication set target_machine—Name of the target machine original_source_machine—Specifies that the replication set was not originated on the curr
Resume Target Command RESUMETARGET Description Allows you to resume the execution of Storage Mirroring operations on the target Syntax RESUMETARGET Options target_machine—The name of the target machine where you want to resume execution of the Storage Mirroring operations Examples resumetarget jersey Notes ! You must be logged on to the target machine for this command to work.
Schedule End Command SCHEDULE END Description Sets criteria to end the transmission of data from the source to the target Syntax SCHEDULE END [ DURATION = ][ BYTES = ] Options ! target_machine—Name of the target machine ! number—Any number indicating the length of time before the transmission ends ! time_units—Minutes (min), hours (hr), or days (day) ! bytes—Number of bytes transmitted before the transmission ends ! schedule jersey end duration=
Schedule Window Command SCHEDULE WINDOW Description Sets criteria to only allow transmissions during a certain period of time Syntax SCHEDULE WINDOW TO Options ! target_machine—Name of the target machine ! hh:mm—Time in hour:minute format using the 24 hour clock. The first time is when the transmission will begin and the second time is when the transmission will end.
Set Local Command SETLOCAL Description The Text Client/DTCL sends a request directly to the registry, bypassing Storage Mirroring, to modify the value of a Storage Mirroring program setting. Syntax SETLOCAL
Statslog Start Command STATSLOG START Description Starts the DTStats statistics logging utility. Syntax STATSLOG START [TO ] [EVERY ] [MAXSIZE ] Options ! machine—Name of the machine ! filename—Any valid path and filename to which the statistical information will be logged ! minutes—The number of minutes to write to the log file ! kilobytes—The maximum file size in kilobytes Examples statslog start indy to dtstat.
Status Command STATUS Description Requests connection and statistical information Syntax STATUS CONNECT | MIRROR | REPLICATE | TRANSMIT Options ! CONNECT—Displays connection information ! MIRROR—Displays mirroring information ! REPLICATE—Displays replication information ! TRANSMIT—Displays transmission information ! con_id—Connection ID assigned to the source/target connection ! status connect 1 status replicate 1 Examples ! Target Command TARGET Description Identifies a mac
TimeNow Command TIMENOW Description Prints the current date and time. Syntax TIMENOW Examples timenow Notes This command is useful for scripting to determine process start and stop times.
Transmission Stop Command TRANSMISSION STOP Description Stops the transmission process Syntax TRANSMISSION STOP Options target_machine—Name of the target machine Examples transmission stop jersey Unload Source Command UNLOAD SOURCE Description Unloads the Storage Mirroring source module Syntax UNLOAD SOURCE Options machine—Name of the machine Examples unload source indy Unload Target Command UNLOAD TARGET Description Unloads the Storage Mirroring target modu
Verify Command VERIFY Description Verifies the integrity of the data between the source and target machines.
Wait on Mirror Command WAITONMIRROR Description This command is used in scripts to force the script to stop executing until the connection has finished mirroring or verifying. Syntax WAITONMIRROR Options con_id—Connection ID assigned to the source/target connection Examples waitonmirror 1 Wait on Restore Command WAITONRESTORE Description This command is used in scripts to force the script to stop executing until the connection has finished restoring.
Write Command WRITE Description Displays the value of a DTCL variable Syntax WRITE $ Options variable_name—The name of the variable that you have established and want to display its value Examples ! write $thetarget ! write $dbrepset A - 37
DTCL Scripting To simplify using Storage Mirroring and DTCL, you can create script files to execute series and combinations of commands to meet specific needs. NOTE: When creating DTCL scripts, each commented line must start and end with the pound (or number) sign (#). Each DTCL command and assignment must end with a semi-colon. However, no semicolon is necessary after the END keyword for the IF conditional and the loop statements.
! WHILE Loop—The WHILE loop evaluates a relational expression and, if it is true, then the statement block is executed. When the statement block has completed execution, the expression will be reevaluated again and, if it is true, the statement block is executed again. This continues until the expression is false.
Error Code Description -122 The replication set you are attempting to create already exists. -123 The replication set you are attempting to delete does not exist. -124 The replication set you are attempting to manipulate does not exist. -125 The connection for which you are attempting to start or resume replication is already replicating. -126 The connection for which you are attempting to stop or pause replication is not replicating.
Error Code Description -205 The monitor set you are attempting to enable is already in use. -206 The monitor you are attempting to use with monitor set does not exist. -209 The machine you are attempting to failback is not failed over. -210 The machine you are attempting to failover is already failed over. -211 The machine you are attempting to failover is not currently being monitored. -213 IP address placeholders on the target are unavailable. -214 The specified target NIC was not found.
DTCL Scripting Examples This section shows examples of different script files. Using batch files To use a Storage Mirroring batch file, you must first create the following one-line batch file which initiates the Storage Mirroring Command Line Client and specifies the name of the script to execute. DataCopy. BAT cd c:\Program Files\OpenView\Storage Mirroring cmd /c DTCL -f "c:\Program Files\OpenView\Storage Mirroring\ scriptname.txt" DataCopy.
Basic restore script The following script will restore the data in the Exchange replication set from the target machine to the source machine. source indy; restore Exchange to jersey nooverwritenewer, usetargetdb; Basic getting started script with variables The following script uses variables to identify the source, target, and replication set. These variables are then used in the DTCL commands. The $connectionID variable will contain the connection ID for the connection established.
B ! Application Failover Application Failover Storage Mirroring simulates application failover by replicating and failing over key application functions like user data, shares, machine names, IP addresses, and so on. Functions like service availability can also be triggered during failover by using Storage Mirroring’s flexible scripting features. These scripts allow you to create and execute scripts on the target machine before and after failover and failback.
Script Sample The following batch file might be used to stop and start Microsoft Exchange services on a Windows machine. This file is just a sample to demonstrate the kinds of commands and functions you can perform using scripts. You will need to modify this script to work in your environment and to achieve the desired outcome. SAMPLE_NT_POSTOVER.
C ! Disaster Recovery for MSCS Disaster Recovery for MSCS A Microsoft cluster is a group of independent servers, called nodes, working together as a unit. Clients interact with a cluster as though it is a single server. When a node in the cluster fails, Microsoft Cluster Server (MSCS) responds by moving the work from the failed node to the other node in the cluster. Microsoft documents and recommends a standard cluster configuration containing two machines sharing a SCSI disk.
MSCS and Storage Mirroring The Microsoft Cluster Server configuration typically contains two machines, called nodes, sharing at least one SCSI disk. Microsoft recommends at least two network interfaces where one or more is dedicated to node to node traffic. The cluster contains resources such as services and devices that are managed by the cluster and allowed to move from one node to the other.
Cluster to Cluster Configuration The following instructions are for a cluster to cluster configuration. Configuring the first cluster For the first cluster you will need to configure the virtual server, install and configure Storage Mirroring and configure the Storage Mirroring replication set. Configure the virtual server on the first cluster Client machines need to access a server when looking for an application, printer, file share, or other resource.
2. Create an IP Address resource for the new group. a. Right-click the group that you just created and select New, Resource. b. Specify the following fields on the New Resource dialog box: ! Name—Specify a name that identifies this resource as the IP address for the group. This name must be unique within the cluster. ! Description—You can optionally add a more detailed description for this resource. ! Resource type—Specify IP Address. ! Group—The resource group name should be selected.
3. Create a Network Name resource for the new group. a. Right-click the group and select New, Resource. b. Specify the following fields on the New Resource dialog box: ! Name—Specify a name that identifies this resource as the virtual server name. This name must be unique within the cluster. ! Description—You can optionally add a more detailed description for this resource. ! Resource type—Specify Network Name. ! Group—The resource group name should be selected.
4. f. Specify the Network Name Parameters by entering the virtual name of the server. This is the name that clients will look for on the network and the name that will register with DNS. It must be unique both on the cluster and on the network. g. Click Finish to complete the creation of the Network Name resource. Create a Physical Disk resource for the new group. a. Right-click the group and select New, Resource. b.
Install and Configure Storage Mirroring on the first cluster 1. If you have not already done so, install Storage Mirroring on the first node of the first cluster using the installation defaults. NOTE: The Storage Mirroring installation will prompt you to reboot the machine. You can reboot at a later time, but in order for Storage Mirroring to function properly and for you to finish these instructions, you must reboot. For complete installation details, see the Getting Started guide. 2.
9. Double-click on the second node on the left pane of the Management Console to login. 10. Right-click the node and select New, Replication Set. 11. Enter the exact, case-sensitive name for the replication set as specified on the first node and press Enter. 12. Because the second node does not currently own the files, you will not be able to browse to select the data like you did on the first node.
Completing the first cluster configuration To finalize the configuration, you need to create a Double-Take Source Connection resource and bring both the virtual server and Source Connection components online. Before beginning, make sure that the resource group and all of its resources are offline on the second cluster. Configure the Double-Take Source Connection resource The Double-Take Source Connection resource controls the Storage Mirroring connections.
! Allow connection scripts to interact with the desktop—Mark this check box if you want to display the connection information in a command prompt dialog box. NOTE: If the script is set to interact with the desktop, the results will be displayed on the owning node. The resource will remain at the Online pending status until the script is manually acknowledged by a user.
Cluster to Standalone Configuration The following instructions are for a cluster to standalone server configuration. Configuring the cluster For the cluster you will need to configure the virtual server, install and configure Storage Mirroring, configure the Storage Mirroring replication set, and create the Double-Take Source Connection resource. Configure the virtual server on the cluster Client machines need to access a server when looking for an application, printer, file share, or other resource.
2. Create an IP Address resource for the new group. a. Right-click the group that you just created and select New, Resource. b. Specify the following fields on the New Resource dialog box: ! Name—Specify a name that identifies this resource as the IP address for the group. This name must be unique within the cluster. ! Description—You can optionally add a more detailed description for this resource. ! Resource type—Specify IP Address. ! Group—The resource group name should be selected.
3. Create a Network Name resource for the new group. a. Right-click the group and select New, Resource. b. Specify the following fields on the New Resource dialog box: ! Name—Specify a name that identifies this resource as the virtual server name. This name must be unique within the cluster. ! Description—You can optionally add a more detailed description for this resource. ! Resource type—Specify Network Name. ! Group—The resource group name should be selected.
4. f. Specify the Network Name Parameters by entering the virtual name of the server. This is the name that clients will look for on the network and the name that will register with DNS. It must be unique both on the cluster and on the network. g. Click Finish to complete the creation of the Network Name resource. Create a Physical Disk resource for the new group. a. Right-click the group and select New, Resource. b.
Install and Configure Storage Mirroring on the cluster 1. If you have not already done so, install Storage Mirroring on the first node of the cluster using the installation defaults. NOTE: The Storage Mirroring installation will prompt you to reboot the machine. You can reboot at a later time, but in order for Storage Mirroring to function properly and for you to finish these instructions, you must reboot. For complete installation details, see the Getting Started guide. 2.
10. Right-click the node and select New, Replication Set. 11. Enter the exact, case-sensitive name for the replication set as specified on the first node and press Enter. 12. Because the second node does not currently own the files, you will not be able to browse to select the data like you did on the first node. Therefore, you will need to manually enter the replication set data that you recorded in the Replication Set Properties table. a.
7. Specify the following on the Double-Take Source Connection Parameters dialog box: ! Replication Set—Specify the name of the Storage Mirroring replication set. This name is case-sensitive and should be the same name as specified in Configure the Storage Mirroring replication set on page C-15. ! Double-Take Target—Specify the name of the standalone target server.
Completing the cluster configuration You will finalize the cluster configuration by bringing the components online. Bring the Components Online From the Cluster Administrator (Start, Programs, Administrative Tools, Cluster Administrator) bring the Double-Take Source Connection resource and the virtual server resources online. Notice the warning signs are removed from the resource and the group. The State column indicates the resource is online and functioning properly.
Standalone to Cluster Configuration The following instructions are for a standalone source server to a cluster target configuration. Configuring the standalone sever 1. If you have not already done so, install Storage Mirroring on the standalone server using the installation defaults. NOTE: The Storage Mirroring installation will prompt you to reboot the machine.
d. Specify zero or one cluster node as the Preferred Owner. Do not specify both nodes. If a preferred node is selected for a resource group, then the group will automatically move to its preferred node when that node comes online. This does not affect manual moves of the group when both nodes are online. NOTE: e. Click Finish to complete the creation of the new group. NOTE: 2.
! Network to use—If you have more than one route for network traffic defined, specify the network that this IP address will use. This should be the same network that the clients are using. g. 3. Click Finish to complete the creation of the IP Address resource. Create a Network Name resource for the new group. a. Right-click the group and select New, Resource. b.
4. f. Specify the Network Name Parameters by entering the virtual name of the server. This is the name that clients will look for on the network and the name that will register with DNS. It must be unique both on the cluster and on the network. g. Click Finish to complete the creation of the Network Name resource. Create a Physical Disk resource for the new group. a. Right-click the group and select New, Resource. b.
Install Storage Mirroring on the cluster 1. If you have not already done so, install Storage Mirroring on the first node of the cluster using the installation defaults. NOTE: The Storage Mirroring installation will prompt you to reboot the machine. You can reboot at a later time, but in order for Storage Mirroring to function properly and for you to finish these instructions, you must reboot. For complete installation details, see the Getting Started guide. 2.
Understanding the Double-Take Source Connection resource The Double-Take Source Connection resource is like other cluster resources. The cluster controls the movement from node to node if there is a failure. This resource additionally controls the Storage Mirroring connection. Therefore, if there are node failures, the Storage Mirroring connection is automatically handled by the new owning node without user intervention.
D ! Glossary Glossary Alerts—Notifications, warnings and errors that describe Storage Mirroring processes. Auto-disconnect—When the Storage Mirroring queue has reached its maximum, the auto-disconnect process empties the source queue and the source/target connection is broken. Auto-reconnect—The process that automatically reestablishes any source/target connections that were active before a Storage Mirroring failure on the source machine.
Replication—The real-time transmission of file changes. Replication Set—The data on a source machine that is to be protected by Storage Mirroring. Replication sets are defined by the volumes, directories, files, or wild card combinations that are to be replicated to the target. Replication Set Rule—One volume, directory, file, or wild card specification that is to be replicated to the target. One or more replication set rules form a replication set.
Index A Active Directory 15-7 active/active 1-8 active/standby 1-7 administrator access 15-1 Management Console 2-5 text clients 3-3 advanced settings Management Console database 14-7 general 14-2 logging 14-9 network 14-4 queuing 14-5 source 14-6 startup 14-3 target 14-7 settings table for text clients 14-11, 14-27 text clients 14-10 all-to-one mapping 6-2 application failover Windows B-2 at-a-glance monitoring 13-5 auto-disconnect D-1 overview 6-6 AutoReconnect 6-18 auto-reconnect D-1 Management Console 6
Failover Control Center configuring failover 11-12–11-16 display 4-2 display refresh rate 11-21 failback 11-18 operations 4-2 overview 4-1 ports 4-5, 11-21 starting 4-1 failure detection 11-5 failure monitoring overview 1-5 features backup 1-2 disaster recovery 1-2 high availability 1-2 other 1-2 resource utilization 1-2 file entry 3-2 G get A-7 getenvstr A-7 getlocal A-7 H hard links 5-4 heartbeats 14-4 help A-8 Management Console 2-9 high availability 1-2 HP OpenView Storage Mirroring overview 1-1 I ic
monitor clear 11-29, A-13 monitor create 11-23, A-13 monitor delete 11-29, A-13 monitor display 11-27, A-14 monitor get A-14 monitor list A-14 monitor move 11-24, A-15 monitor option 11-25, A-16 monitor remove 11-25, A-18 monitor script add 11-26, A-18 monitor script remove 11-27, A-19 monitor start 11-28, A-19 monitor stop 11-28, A-20 monitor use 11-24, A-20 monitoring connection Management Console 6-9 failover 4-3, 11-17 mirroring Management Console 7-8 replication Management Console 8-4 verification Mana
restoration automating 12-9 conditionals 12-3 conditionals compared 12-4 how it works 12-2 Management Console 12-5 options 12-3 options compared 12-4 overview 1-6, 12-1 text clients 12-7 restore 12-8, A-28 resume target A-29 resync replication set 5-16 route 6-2, 6-7 rules 5-1 S saving replication set Management Console 5-6, 5-7, 5-9 text clients 5-11, 5-16 schedule options 10-2 window option 10-3 schedule clear 10-9, A-29 schedule disable 10-9, A-29 schedule enable 10-9, A-29 schedule end 10-11, A-30 sche
on connection Management Console 9-5 options 9-1 overview 9-1 remirror options 9-1 remirror options compared 9-2 text clients log 9-10 manually initiating 9-10 verify 9-10, A-37 VerifyLogAppend 9-11 VerifyLogLimit 9-11 VerifyLogName 9-10 W wait A-37 waitonmirror A-38 waitonrestore A-38 waitontarget A-38 wild cards 5-7 window 10-3 write A-39 V
