HP StorageWorks Continuous Access XP user guide for the XP10000/XP12000 Part number: T1711-96003 Second edition: December 2005
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Contents About this guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Firmware versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Related documentation . . . . . . . . . . . . . .
Cache and nonvolatile storage (NVS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Host failover software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Duplicate volumes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Host system crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deleting consistency groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Usage Monitor operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Starting and stopping monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Starting remote copy usage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 Tables 1 2 3 4 6 Serial remote copy connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 N pairs of remote copy connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 N-to-1 and 1-to-n remote copy connections (n £ 4) . . . . . . . . . .
operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Continuous Access XP Asynchronous pair status descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Continuous Access XP split types (PSUS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Consistency status descriptions for split/suspended Continuous Access XP Async S-VOLs . . . . . . . . . . .
About this guide This guide provides information about the following: • Understanding Continuous Access XP operations • Preparing for Continuous Access XP operations • Installing hardware • Combining Continuous Access XP with other data management operations • Using Continuous Access XP • Performing Continuous Access XP configuration operations • Performing Continuous Access XP pair operations • Performing Continuous Access XP disaster recovery operations • Understanding error codes and messages • Recoverin
• HP StorageWorks External Storage XP User Guide • HP StorageWorks LUN Configuration and Security Manager XP User Guide for the XP10000/XP12000 • HP StorageWorks LUN Security XP Extension User Guide • HP StorageWorks Performance Control User Guide • HP StorageWorks XP Disk/Cache Partition User Guide • You can find these documents at http://www.hp.
• Operating system type and revision level • Detailed, specific questions For continuous quality improvement, calls may be recorded or monitored. Subscription service HP strongly recommends that customers register online using the Subscriber’s choice web site at http://www.hp.com/go/e-updates.
1 Continuous Access XP for the XP10000/XP12000 HP StorageWorks Continuous Access XP creates and maintains duplicate copies of user data from a local disk array on a remote disk array. These copies are useful for data duplication, backup, and disaster recovery. Continuous Access XP has synchronous and asynchronous copy modes to accommodate a wide variety of user requirements and data copy or movement scenarios. Continuous Access XP is used for open systems data.
• ”Continuous Access XP Asynchronous recordset operations” on page 21 • ”Continuous Access XP Asynchronous consistency group operations” on page 23 • ”Continuous Access XP volume pair status” on page 25 Components Continuous Access XP operations involve the XP10000/XP12000 at a primary and secondary (remote) site, physical communications paths between these disk arrays, and Command View XP or XP Remote Web Console.
Figure 2 Continuous Access XP components for Serial (ESCON) connections XP10000/XP12000 Continuous Access XP operations involve primary (main) disk arrays and secondary (remote) disk arrays (MCUs and RCUs). This document describes Continuous Access XP operations in which the main disk array is an XP10000/XP12000 and the remote disk array is an XP10000/XP12000. MCUs contain Continuous Access XP primary volumes (P-VOLs), which contain original data and are online to the hosts.
reported if a problem with a secondary volume or remote disk array occurs and provide disaster recovery capabilities. You can define the MCU and RCU whether or not you specify the CU image. To define the MCU and RCU and specify the CU image, specify the desired CU image. To define the MCU and RCU without specifying the CU image, specify CU Free. For more information, see ”Registering RCUs (Add RCU)” on page 64. The MCU and RCU can be defined separately for each Continuous Access XP volume pair.
XP Async volume pair must be assigned to a consistency group. Continuous Access XP can configure up to 128 consistency groups (0-7F) for each MCU and provides group-based operations for consistency groups (for example, split and resync group). Use consistency groups to maintain update sequence consistency for databases spanning multiple volumes, allowing immediate database recovery at the remote site when needed.
• CU Free if you set the MCU-RCU path and specify CU Free. For more information, see ”Preparing for disaster recovery” on page 105. Initiator ports and RCU target ports Initiator ports are dedicated Fibre Channel interface ports on the main disk array (MCU) to which RCUs (RCU target ports) are connected. Initiator ports connect to RCUs to send write I/O operations directly to RCUs. You can configure Fibre Channel interface ports of the XP10000/XP12000 as initiator ports.
depending on your installation requirements and standards. Command View XP or XP Remote Web Console does not provide host failover functions. When Continuous Access XP is used as a data migration tool, host failover is recommended but not required. When Continuous Access XP is used as a disaster recovery tool, host failover is required to ensure effective disaster recovery operations.
• A write command whose data length is short enough not to pass the track-end • Write data to the track-end, whose total length is long enough to pass the track-end • Write data to the last track for the command NOTE: No matter how long the write data is, update copy is executed for each track. For asynchronous update copy mode, the MCU stores P-VOL updates with additional control information in cache, and sends updates and control information to the RCU completely independent of host I/O processes.
S-VOL write option Continuous Access XP provides an S-VOL write option that enables write access to the S-VOL of a split Continuous Access XP pair. The S-VOL write option can be selected during the pairsplit-r operation and applies only to the selected pairs. The S-VOL write option can be accessed only when you are connected to the MCU.
The MCU does not remove the sidefile entry for a recordset from its cache until it receives an I/O completion signal (device end) from the RCU. This is true even if the MCU and RCU are connected via a channel extender product. If a recordset is lost in transmission from the MCU to the RCU, the MCU’s cylinder bitmap ensures that the missing recordset is identified and resent to the RCU.
• Offloading Timer (sec.): Maximum time between Continuous Access XP Async recordset transfers. • I/O Delay Start (%): Maximum amount of cache for starting I/O inflow control. • I/O Delay Increase (%): Maximum amount of cache for starting to strengthen control over I/O inflow. Inflow control by MCU When the amount of MCU sidefile cache reaches the user-specified threshold (I/O delay start), the disk array’s I/O response is delayed.
• Group consistency time • Group operations Group options Continuous Access XP provides the following options for each consistency group: copy pending timeout and RCU ready timeout. These options are selected when you add a group, and can be modified only when the group does not contain any P-VOLs in the MCU. Copy pending timeout This group option specifies maximum delay allowed for Continuous Access XP Async copy operations.
error level should not be used for disaster recovery because they are not consistent with the rest of the volume group. Continuous Access XP volume pair status Continuous Access XP displays pair status for each volume in the selected logical CU image (CUI) of the connected XP10000/XP12000. Table 5 describes Continuous Access XP pair status descriptions. The MCU maintains the status of the P-VOL and can change the pair status of the P-VOL and S-VOL.
Table 5 Continuous Access XP Asynchronous pair status descriptions (continued) Pair status Description P-VOL access S-VOL access PSUS (pair suspended-split) Pair is not synchronized because you split this pair (pairsplit-r) or deleted this pair from the RCU (pairsplit-S). For Continuous Access XP Async pairs, the MCU and RCU track recordsets discarded during the pairsplit-r operation. While a pair is split, the MCU and RCU track P-VOL and S-VOL cylinders updated.
Table 5 Continuous Access XP Asynchronous pair status descriptions (continued) Pair status Description P-VOL access S-VOL access Read/write Read only Pair Status for Continuous Access XP LUSE volumes only: PDUB Continuous Access XP pair consists of LUSE volumes (for example, OPEN3*n), and an individual LDEV within this Continuous Access XP LUSE pair failed due to some error condition.
A split (or suspended) Continuous Access XP Async S-VOL has an additional status called consistency status. The consistency status is displayed only at the RCU and indicates the S-VOL’s update sequence consistency with respect to other S-VOLs in the same group. Table 6 Continuous Access XP split types (PSUS) Type Applies to Description PSUS, P-VOL by Operator P-VOL (Continuous Access XP Sync only) You split the pair from the MCU using the P-VOL Failure option. S-VOL split type is PSUS-by MCU.
When a Continuous Access XP Sync pair is suspended, the MCU stops performing update copy operations to the S-VOL and may or may not continue accepting write I/Os for the P-VOL, depending on the P-VOL fence level pair option. If a synchronous update copy operation fails, the MCU maintains exact synchronization by reporting a unit check and decommitting the P-VOL update. The host system and application program regard that write operation to the P-VOL as failed.
Continuous Access XP Asynchronous suspension conditions Continuous Access XP Asynchronous operations involve additional suspension conditions related to recordset operations. The MCU and RCU detect Continuous Access XP Async suspension conditions and suspend Continuous Access XP Async pairs.
Preparing for Continuous Access XP operations System requirements Continuous Access XP operations involve MCUs and RCUs containing primary and secondary volumes, remote copy connections between MCUs and RCUs, UNIX and/or PC server hosts at primary and remote sites, and Continuous Access XP. You can use the Command View XP management station or XP Remote Web Console to manage MCUs and RCUs. Continuous Access XP system requirements are: • MCU: Disk array with Continuous Access XP installed.
not support operations in which one P-VOL is copied to more than one S-VOL or more than one P-VOL is copied to one S-VOL. Because Continuous Access XP operates on logical volumes rather than files, multivolume files require special attention.
disk array cache to adequately support Continuous Access XP remote copy workloads and local workload activity. Host failover software Host failover software is a critical component of any disaster recovery effort. When an MCU fails to maintain synchronization of a Continuous Access XP pair, the MCU generates sense information. This information must be transferred to the remote site via the host failover software for effective disaster recovery.
Ensure that adequate cache is installed and available for all open systems and mainframe asynchronous mirroring operations. Also consider the amount of HP Cache LUN XP data to be stored in cache when determining the required amount of cache. 4. HP representative: Ensure that MCUs are configured to report sense information to hosts. RCUs should also be attached to a host server to enable reporting of sense information if a problem with an S-VOL or RCU occurs.
Fibre Channel interface connection provides the following configurations: • Direct connection: Two devices are connected directly. Figure 6 Direct connection • Switch connection: Up to three optical fibre cables (per hard zone) are connected via switches to connect the devices. Up to two switches can be used. Figure 7 Switch connection • Extender connection: Protocol converters and switches are used to connect devices across large distances.
43 km (26.7 miles) using standard ESCON support. Long-distance solutions are provided using approved channel extenders and communication lines. Figure 9 Serial remote copy connections You can install dedicated ESCON channels or use existing ESCON channels connected by ESCDs. Logical paths between the MCU and RCU must be separate from logical paths between the host and RCU. All remote copy activities between two XP disk arrays can share the same remote copy connections.
NOTE: 1-to-n configurations (one main disk array and multiple remote disk arrays) are valid for Continuous Access XP Asynchronous, as long as a consistency group does not span remote disk arrays. ESCDs can accommodate channel-to-MCU and channel-to-RCU connections in addition to remote copy connections (see Figure 12).
6. For FC configurations, configure Fibre Channel ports connected to RCUs as initiator ports. For serial interface configurations, configure serial channel ports connected to RCUs as RCPs. For instructions, see ”Port change operation” on page 74. 7. Register the RCUs to the current MCU CU image by using the Add RCU pane. Set the options for the registering RCU by using the RCU Option pane (see ”Registering RCUs (Add RCU)” on page 64 for instructions). Figure 13 Add RCU and RCU Option panes 8.
NOTE: If you are using Command View XP, proceed with step 9. If you are using XP Remote Web Console, no other actions are required. 9. When you are finished configuring this MCU, exit the Continuous Access XP main pane, and disconnect the Command View XP management station from the disk array. 10.If needed, reconnect Performance Advisor to this disk array (running PA at the same time is not supported). 11.Repeat step 4 - step 9 for each disk array that will function as a Continuous Access XP MCU.
BC is recommended for intra-disk array copy operations. If BC is not installed, use Continuous Access XP (Synchronous only) to copy within the same disk array. This configuration requires at least one external fibre cable or ESCON loop. • Prioritized Port Control. Initiator ports in the MCU do not support the Prioritized Port/WWN Control option. Combining Continuous Access XP and Auto LUN XP Auto LUN XP provides detailed information about I/O activity and hardware performance of local disk arrays.
Use Continuous Access XP and BC in the same disk array and on the same volumes to provide multiple copies of data at primary and remote sites. Table 10 describes host pair status reporting for Continuous Access XP volumes, BC XP volumes, and Continuous Access XP/BC shared volumes. Table 11 shows currency of data on a shared Continuous Access XP/BC volume based on Continuous Access XP and BC pair status.
• Figure 15 shows an example of a Continuous Access XP P-VOL that also functions as a BC P-VOL. With this configuration, use BC for on-site data backup if a Continuous Access XP failure occurs, and use Continuous Access XP to provide remote backup of the BC P-VOL if a BC failure occurs. Figure 15 Shared Continuous Access XP P-VOL and shared BC P-VOL • Figure 16 shows an example of a Continuous Access XP S-VOL that also functions as a BC P-VOL.
Combining Continuous Access XP and LUN Security XP Extension You can use Continuous Access XP to create a pair using the volumes that you used LUN Security XP Extension to set the access attribute. However, you cannot create a Continuous Access XP pair by specifying a volume that has the S-VOL Disable attribute as an S-VOL. Table 12 shows whether you can specify a volume with access attribute as a P-VOL or S-VOL of a Continuous Access XP pair.
Figure 19 shows the process of the copying of access attribute when you create a pair using the volumes with VMA. Figure 19 Copying access attributes As you can see in Figure 19, if both the P-VOL and S-VOL have VMA, the P-VOL’s VMA is copied to the S-VOL. In Figure 19, the S-VOL’s access attribute is Read/Write when the pair status is SMPL. After the P-VOL’s VMA is copied to the S-VOL, the S-VOL’s access attribute becomes Read Only, which is the same as the P-VOL’s access attribute of the P-VOL.
NOTE: If the pair is suspended or deleted during the COPY status, the P-VOL’s access attribute is not copied to the S-VOL. To copy the P-VOL’s access attribute to the S-VOL, ensure that the pair status is PAIR, and suspend or delete the pair. NOTE: When the P-VOL is in the COPY or PAIR status, there are two access attributes that can and cannot be changed according to the existing access attribute. For more information about the variable access attribute, see Table 15.
NOTE: If the license capacity for LUN Security XP Extension is insufficient in the disk array on the secondary site, you might not be able to create Continuous Access XP pairs. For more information about the license capacity for LUN Security XP Extension, see the HP StorageWorks LUN Security XP Extension User Guide. Starting Continuous Access XP You must operate Command View XP or XP Remote Web Console in Modify mode to perform Continuous Access XP operations.
Table 16 shows the Continuous Access XP functions of each tab. To apply settings on the Continuous Access XP function tabs, click Apply. Table 16 Continuous Access XP functions Tab Menu Command Description Pair Operation Pairdisplay Displays CU information, path information, pair status, and settings information about Continuous Access XP pairs. Monitoring LDEV status is not supported. Paircreate > Synchronous Sets new Continuous Access XP Synchronous pairs.
Continuous Access XP functions (continued) Table 16 Tab Menu Command Description History Operations — Displays operation history of Continuous Access XP volume pairs. Other Operation NOTE: Changes option settings of the subsystem. The scripting function is not supported for this version. Continuous Access XP main pane (Pair Operation pane) The first pane that appears after clicking the CA tab is the Continuous Access XP main pane, also known as the Pair Operation pane.
To change the number of items that can be displayed without scrolling, change the font size. NOTE: Figure 21 Volume list (partial view) • Volume icon: Status of volumes. Table 17 shows the icons. Table 17 Icon Volume icons for Continuous Access XP operations Explanation SMPL P-VOL S-VOL • Port, G-ID, and LUN: Port number, LU host group number and name, and LU number (LUN). NOTE: If # is added to the end of an LDEV number, such as 00:3C#, the LDEV is an external volume.
• Sub: Suspend Sub Status. • Grp: Sequence number of current volume is same as consistency group. • LU: Sequence number of current volume is not same as consistency group. • OFF: Suspended by the PS OFF by the MCU. • S/N and ID: Serial number and SSID of the other disk array (MCU or RCU) of the volume pair. • Port, G-ID, and LUN: Port number, LU host group number and name, and LUN of the other volume of the volume pair. If the LU is set to more than one path, the LU specified at paircreate is displayed.
specification on the Display Filter pane for the CU number or Group number is not available. To make all settings on the Display Filter pane available, click Subsystem in the CU Number/Port Number tree. Figure 22 Display Filter pane The Display Filter pane contains the following drop-down lists: • G-ID, Port, and CU: Number of group, port, and CU to be displayed. • Type: Pair type: Synchronous or Asynchronous. • P-VOL/S-VOL: Volume type: P-VOL or S-VOL.
NOTE: You can use the Snapshot function only while client file access is enabled. When client file access is not enabled, the Snapshot button is not displayed on the Pair Operations pane. Table 19 describes the Snapshot functions. Table 19 Snapshot functions Item Function Data Format Text file. Target data The Continuous Access XP pairs being reported are determined by selections on the Display Filter pane.
The RCU Operation pane is updated when the tab is switched from one to another, Refresh is clicked, and settings for the RCU are applied. For the RCU settings operation, see ”RCU operations” on page 61. Figure 23 RCU Operation pane The RCU Operation pane contains the following items: • Switch Display options: • MCU&RCU: Displays the CU Number tree and MCU/RCU list (see ”CU Number tree and MCU/RCU list” on page 53). The MCU/RCU list is displayed by default.
• CU#: CU number selected on the tree. • Type: MCU or RCU. • S/N and SSID: Serial number and SSID of the other CU of the pair. • Paired CU#: CU number of the other CU of the pair. • M-R Path: Path channel type (Fibre or Serial) between the other CU of the pair. • Status: Normal indicates no failure path between the RCU. Failed indicates there are failure paths between the RCU. This column is blank when the pair CU is MCU. • Num. of Path: Number of paths. This column is blank when the pair CU is MCU.
The Asynchronous Operation pane is updated when the tab is switched from one to another, Refresh is clicked, and settings are applied. Figure 26 Asynchronous Operation pane The Asynchronous Operation pane contains the following items: • Consistency Group tree: All consistency groups (default), only consistency groups already in use (Used), or consistency groups available for use (Not Used). • Consistency Group list: Consists of the following items: • CTG: Consistency group number.
Usage Monitor pane The Usage Monitor pane displays user-selected remote copy I/O statistics and status of remote copy usage monitoring, and provides access to the Continuous Access XP usage monitor operations (see ”Usage Monitor operations” on page 82). The Usage Monitor pane is updated when the tab is switched from one to another, Refresh is clicked, and settings are applied. Figure 27 Usage Monitor pane The Usage Monitor pane contains the following items: • Status: Displays Running when monitoring is on.
The History Operations pane is updated when the tab is switched from one to another, Refresh is clicked, and settings are applied. Figure 28 History Operations pane The History Operations pane contains the following items: • Status: Current status of history file. Possible values: • No history file exist: History file does not exist. • Reading a history failed: Failure occurred when referring to history file. • Update history ... n (%): History file update is in progress.
• Paired VOL: CU number and LDEV number of paired volume. • Copy Time: Time taken for operation (from start of operation to end). Displayed only for Pairing Complete and Pair Resync. Complete operations. NOTE: For Continuous Access XP pairs consisting of LUN Expansion (LUSE) volumes, number of Pair Suspend (Failure) rows in the history list does not correspond to number of LDEVs in the LUSE volume. For LUSE volumes with three or more LDEVs, only two rows showing Pair Suspend (Failure) are displayed.
Changing subsystem settings Use the Other Operation tab to change subsystem settings. Viewing subsystem settings 1. In the Continuous Access XP main pane, click Other Operation. The Other Operation pane displays the Tree. 2. Click a subsystem from the Tree. The Preset List displays subsystem settings. • Activity: Number of volumes in concurrent initial copy operations. It can be between 1 and 128. • Path Watch: Time for monitoring blockade in the paths (0 to 45 seconds).
default setting is 70 seconds. The value of the Path Blockade SIM Watch cannot be smaller than the value of the Path Blockade Watch. Figure 31 System Option pane Changing subsystem settings 1. In the Continuous Access XP main pane, click Other Operation. The Other Operation pane displays the Tree. 2. Click a subsystem from the Tree. The Preset List displays subsystem settings. 3. Right-click the list, and select System Option. Current settings appear. 4. Select Set to close the System Option panel.
• ”Deleting consistency groups (Delete CT Group)” on page 79 • ”Usage Monitor operations” on page 82 collect I/O statistics for LDEVs on a disk array • History operations display Continuous Access XP history file • ”Optimizing Continuous Access XP operations and disk array performance” on page 85 • ”Discontinuing Continuous Access XP operations” on page 86 The Continuous Access XP main pane provides access to all Continuous Access XP volume pair operations: creating pairs, splitting and resyncing pairs, and
• ”Adding and deleting SSIDs for RCUs (Add SSID/Delete SSID)” on page 73 Use the RCU Operation pane to perform RCU operations. All operations that can be performed from the RCU Operation pane have the following common procedure: 1. Click the CU number or Package number in the tree. 2. Click one or more RCUs or Packages in the list. For registering RCU operation, the RCU does not have to be selected. For this step, the list can be blank. 3. Right-click the list, and perform one of the following: a.
If you select more than one RCU in step 2, only the RCU Operation command can be selected. Select one RCU in step 2 to display status information. Figure 32 RCU Status pane • Path list: • No.: Path number (serial number of the list). • Path Status: Path status. Normal is displayed when path status is normal. • RCU S/N: Serial number of RCU. • SSID: SSID of RCU. • RCU CU#: CU number of RCU. • MCU-RCU Path: Channel type: Fibre or Serial.
Table 20 Logical path status (continued) Status description Condition Communication Timeout Timeout error occurred between the MCU and RCU. Resource Shortage Establish logical path link function was rejected by the RCU. All logical path resources in the RCU might be used for other connections. Serial Number Mismatch Serial number of the control unit connected to this logical path does not match serial number specified by the Add RCU pane.
NOTE: If four RCUs (maximum number of RCUs you can register) are already registered, you cannot select Add RCU. Figure 33 Add RCU pane • RCU S/N: Serial number of RCU being registered. S/N is five digits. • Controller ID: Controller ID of RCU being registered. • Logical Adr. (RCU CU#): CU number of RCU being registered. CU number is 0-1F. • Path Gr.ID: Used to enter the path group ID for using CU Free.
• Cancel button: Cancels settings made on the Add RCU pane, and closes the pane. Figure 34 RCU Option pane Use the RCU Option pane to set the options for the RCU. • Minimum Paths: Minimum number of paths required for each RCU connected to the current MCU. The default is one. If you specify a number that is larger than the number of paths set on the Register RCU pane or the number of paths falls below this number (for example, failed path), an error occurs.
When an initial copy operation is in progress, the copy pace is automatically adjusted based on the actual time required for initial copy, which can be obtained by subtracting the specified Round Trip Time (obtained using the formula below) from the remote I/O response time. If the actual time required for the initial copy operation is large, the update copy workload is relatively high. Therefore, the copy pace of the initial copy is slowed.
Example settings Table 22 Item No. Round trip time [ms] Line speed between MCU/RCU [MB/ms] Number of lines between MCU/RCU Initial copy pace Maximum number of initial copy VOLs Round trip time specified [ms] 1 0 0.1 4 15 64 160 2 30 0.1 4 15 64 220 3 100 0.1 4 15 64 360 Registering RCUs to the connected MCU 1. Ensure that remote copy connections and MCU ports are properly configured. Get the S/N of the RCU and the SSIDs for the CU image in the RCU.
When the pair option is set (the RCU Option pane is closed), the list changes to the RCU Settings Parameter list. Figure 35 shows the items in the RCU Settings Parameter list. Figure 35 RCU Settings Parameter list • S/N: RCU serial number • SSID 1 to SSID 4: Selected SSID: SSID 1 to SSID 4 • M-R Path: Channel type • Num. of Path: Number of the paths used • MCU Port 1 to MCU Port 8: Port number on the MCU side: 1 to 8 • RCU Port 1 to RCU Port 8: Port number on the RCU side: 1 to 8 • Min.
5. Click Set to set the modifications. The list changes to the RCU Settings Parameter list (RCU Option) view. Click Cancel to cancel all modifications you made. NOTE: After being set, options can be modified and canceled (see ”Modifying parameters and deleting settings” on page 75). 6. Click Apply on the Continuous Access XP main pane to apply the modification to the disk array. When modifications are set (the RCU Option pane closes), the MCU/RCU list changes to the RCU Settings Parameter list (RCU Option).
and Figure 39 show Fibre Channel interface connections going through switches and the Continuous Access XP pane used for this configuration.
Adding and deleting logical paths for RCUs (Add Path/Delete Path) Use the Add Path and Delete Path commands to add and delete paths for an RCU. When the Add Path command is selected, the Add Path pane appears. Figure 40 Add Path pane The MCU-RCU Path field includes: • MCU Port: MCU port number. The Initiator and RCP are listed in the drop-down list and can be selected. • RCU Port: RCU port number. The RCU Target port must be specified. • Link Address: Link address (serial only).
NOTE: After being set, options can be modified and canceled (see ”Modifying parameters and deleting settings” on page 75). 7. Click Apply on the Continuous Access XP main pane to apply the settings to the disk array. The MCU automatically begins using the new logical path for Continuous Access XP activities.
3. To add SSIDs: a. Right-click, and click Edit SSID(s)&Path(s). b. Right-click, and click Add SSID. The Add SSID pane appears. c. Enter new SSIDs in the SSID fields. You can add up to four SSIDs to the RCU. d. Click Set to add the SSIDs. The list changes to the SSID Settings Parameter list. The added SSIDs are listed. NOTE: After being set, options can be modified and canceled (see ”Modifying parameters and deleting settings” on page 75). 4. To delete SSIDs: a. Right-click, and click Edit SSID(s)&Path(s).
NOTE: • Before changing the operation type of a Fibre Channel port from Target or RCU Target to Initiator, disconnect the port from the host, delete all affected Continuous Access XP pairs, delete all paths from the port (if RCU target) to the MCU, and remove all channel paths to the port.
1. Click a consistency group mode (Show ALL, Used, or Not Used) to be operated in the Consistency Group tree. 2. Click one or more consistency group to be operated in the Consistency Group list. 3. Right-click.
• Port, G-ID, and LUN: Pairs in the connected CU that are in selected consistency group. The Group column shows the host group name in parentheses. The LUN column shows the CU:LDEV in parentheses. For LUs with more than one path, only the first path is listed. NOTE: If # is added to the end of the LDEV number, such as 00:3C#, the LDEV is an external volume. For details about external volumes, see the HP StorageWorks External Storage XP User Guide. • MCU-RCU Path: Channel type: fibre or serial.
Async RCU ready). The default is five minutes. If the MCU cannot re-establish communications with the RCU within the specified time, the MCU suspends all P-VOLs in the group. • Cancel button: Cancels settings. • Set button: Sets consistency group options. 1. Connect to the MCU. 2. Ensure that async options are configured as needed (see ”Asynchronous copy option” on page 80). 3. From the Consistency Group tree, click a consistency group mode that includes the consistency group to be added. 4.
S-VOLs in the group. A timeout occurs when the RCU cannot settle a recordset within the specified time or has not had any communications from one of the MCUs in the group within the specified time. NOTE: The copy pending timeout value should be less than the I/O timeout value of the host system. • Time Out (RCU Ready) (min.): Maximum delay allowed for re-establishing MCU-RCU communications following MCU power-off (none or from 1 to 10 minutes; none = no timeout for Continuous Access XP Async RCU ready).
3. From the Consistency Group list, click the consistency groups to be deleted. Select more than one consistency group with MCU in the This CU column. 4. Right-click, click CT Group Operation, and click Delete CT Group. The list changes to the Consistency Group Settings Parameter list. If the Delete CT Group command is not enabled, the selected group still contains P-VOLs in this MCU.
When channel-extenders are used for Continuous Access XP Async, the offloading timer should be set to 35 seconds or less to avoid affecting host I/O performance. • I/O Delay Start: Threshold (0-70%), which is maximum amount of cache for starting inflow control for the asynchronous copy. When amount of cache used for async recordsets reaches the specified threshold, the MCU controls the cache inflow.
Deleting consistency groups 1. Click the consistency groups on the list. 2. Right-click, and click Delete. Selected consistency groups are deleted from the list, and the consistency groups are out of operations. 3. Click Apply on the Continuous Access XP main pane to apply the deletion to the disk array. For the CT Group operation, the Cancel All command deletes all consistency groups on the list, and all consistency groups are removed from operations.
2E8 = 2x108 = 200,000,000. The Update area displays the most recent data sample time for data on the graph. 1. Click the Usage Monitor tab. 2. Verify that usage monitoring is running (Status = Running). The usage monitor graph can be displayed only when monitoring is on. 3. Right-click the graph area, and click Display Item. The Display Item pane appears. Figure 49 Display Item pane 4. To display I/O statistics for all LDEVs in the subsystem, click Subsystem Total.
• To return the graph to normal size, right-click the graph, and click Normal Size. NOTE: When you click Normal Size, the host group name (up to 8 characters) appears at the top of the graph. To check the host group name, enlarge the graph. • To stop displaying the usage monitor graph, right-click the graph, and click Close. • To stop displaying all graphs, click Close All. Table 23 Remote copy I/O statistics Statistic Description RIO count All RIO count Total number of remote I/Os.
Table 23 Remote copy I/O statistics (continued) Statistic Description Synchronization Pair Synchronized (%) Percent completion of initial copy operations. For example, number of synchronized pairs/total number of pairs. Out of Synchronous Tracks Number of tracks that have not yet been copied by initial copy or resync copy operations. This applies only when suspended during initial copy or during resync copy.
Table 24 lists conditions affecting disk array performance and provides recommendations for addressing these conditions. Table 24 Disk array performance conditions and recommendations Condition Description Recommendations Write-intensive workloads Write-intensive workloads, such as database logging volumes, can have a significant impact on disk array I/O response times. Spread write-intensive data across several volumes to minimize queuing.
Continuous Access XP pairs still using that path, and you cannot delete a group until you delete all Continuous Access XP Asynchronous pairs in that group. 1. Delete all Continuous Access XP pairs from MCUs (pairsplit-S, see ”Deleting Continuous Access XP volume pairs (Pairsplit-S)” on page 99). For Continuous Access XP Async pairs, use the Delete Range-Group option to delete all pairs in a group at one time. Verify that the pair status changed to SMPL for all Continuous Access XP volumes before continuing.
Alternatively, you can access XP Remote Web Console directly on the MCUs and RCUs to manage their respective disk arrays. Common procedure for Continuous Access XP pair operations Use the Continuous Access XP main pane to perform pair setting operations. All operations performed from the Continuous Access XP main pane have the following common procedure: 1. Click a CU number in the CU Number/Port Number tree. NOTE: You must select a CU number in the tree.
Modifying LU parameters 1. Click the LU on the Pair Settings Parameter list. 2. Right-click, and click Modify. A pane appears. 3. Modify parameters, and click Set. 4. Click Apply on the Continuous Access XP main pane to apply modifications. Deleting LUs 1. Click the LUs on the Pair Settings Parameter list. 2. Right-click, and click Omit. LUs selected in step 1 are deleted from the Pair Settings Parameter list, and deleted LUs are out of pair settings operations. 3.
NOTE: If an LDEV number contains # at the end (such as 00:3C#), the LDEV is an external volume. For more information about external volumes, see the HP StorageWorks External Storage XP User Guide. • CLPR: CLPR number and name of the volume on the primary site. • Group name: Host group name of the volume on the primary site.
NOTE: Select the appropriate CU image before creating Continuous Access XP pairs. Figure 51 Paircreate pane • Port - Group - LUN: • P-VOL: Port - Group - LUN of the primary volume (P-VOL), CLPR number, and CLPR name. NOTE: If # is added to the end of the LDEV number, such as 00:3C#, the LDEV is an external volume. For details about external volumes, see the HP StorageWorks External Storage XP User Guide. • S-VOL: Secondary volume (S-VOL).
• Asynchronous Parameters: Only for Asynchronous pairs. • CT Group: Consistency group already registered. NOTE: Only Continuous Access XP Asynchronous pairs belonging to the same CLPR can be allocated to one consistency group. For more information about CLPRs, see the HP StorageWorks XP Disk/Cache Partition User Guide. • Error Level: Error level for Continuous Access XP Async pairs, Group, or LU. • Cancel button: Cancels settings made, and closes the Paircreate pane.
CAUTION: If a timeout error occurs when the Use Time-Saving Mode option is selected, access the Continuous Access XP main pane, and confirm the volumes on which the paircreate operation could not be performed. Deselect the Use Time-Saving Mode option for failed volumes, and retry the paircreate operation. After the Paircreate pane closes, the list changes to the Pair Settings Parameter list (Paircreate).
• No Copy: The initial copy operation is not performed. The MCU performs update copy operations as needed. CAUTION: Ensure that the P-VOL and S-VOL are already identical when using this setting. Initial Copy Pace: Maximum number of tracks (1-15) that can be copied at one time by the Continuous Access XP initial copy operation before the MCU accepts another host request for that P-VOL.
information about split Continuous Access XP pairs, see ”Continuous Access XP split types (PSUS)” on page 27. Figure 53 Pairsplit-r pane • Volume: Port - Host group - LUN of the selected volume. NOTE: If # is added to the end of the LDEV number, such as 00:3C#, the LDEV is an external volume. For details about external volumes, see the HP StorageWorks External Storage XP User Guide. • S-VOL Write: Default is Disable.
• Pending Update: Drain: The MCU changes the Continuous Access XP Async pair status from Suspending to PSUS only after the RCU accepts the pairsplit operation and completes the following steps: (a) Finishes settling all pending recordsets for the pair. (b) Completes negotiation with all MCUs (report ready-for-suspension to all MCUs and receive acknowledgements) without further recordsets generated.
When the Pairsplit-r pane closes, the list changes to the Pair Settings Parameter list (Pairsplit-r). Figure 54 Pair Settings Parameter list (Pairsplit-r) The Pair Settings Parameter list (Pairsplit-r) displays the following information for selected pairs: • Port, Group (TID), and LUN of the LU in the connected disk array. • S/N and SSID of the RCU (MCU if connected to the RCU). • S-VOL Wrt: Disable or enable. Enable means the S-VOL is available to receive read and write I/Os.
• P-VOL: Port - Host group - LUN of the selected volume. NOTE: If # is added to the end of the LDEV number, such as 00:3C#, the LDEV is an external volume. For details about external volumes, see the HP StorageWorks External Storage XP User Guide. • P-VOL Fence Level: Fence level. • Never: Never fence the operation. • Data: Fence when the MCU cannot successfully execute an update copy operation for any reason. • Status: Fence only if the MCU cannot change the S-VOL status to the same status as the P-VOL.
NOTE: To resync all split/suspended Continuous Access XP Async pairs in a consistency group, ensure that the Resume range option on the Pairresync pane is set to Group. 7. To execute pairresync requests quickly, select the Use Time-Saving Mode check box above the Pair Settings Parameter list (Pairresync). 8. Click Apply on the Continuous Access XP main pane to resync specified pairs. 9.
RCU, delete the pair from the MCU, and create the pair from the MCU using the appropriate initial copy option (Entire or No Copy) to restart the pair. To delete all Continuous Access XP Async pairs in a consistency group, delete pairs from the MCU. The Continuous Access XP pair status changes to Deleting when the pairsplit-S operation is accepted by the MCU and RCU, and changes to SMPL after the internal pairsplit-S process is complete.
• C/T (RCU only): The RCU deletes all Continuous Access XP Async pairs with the same consistency time. • LU (MCU or RCU): The MCU and RCU deletes only the specified Continuous Access XP Async pairs. Use this option to remove individual volumes from consistency groups.
• Range: Range for deleting the asynchronous pair: Group, LU, or C/T. Changing pair options (Change Pair Option) Use the Change Pair Option command to change pair options, Fence level and Error level (asynchronous pairs only). When the Change Pair Option command is selected, the Change Pair Option pane appears. From the Change Pair Option pane, change pair options. Figure 59 Change Pair Option pane • Volume: Port - Host group - LUN of the selected volume.
NOTE: After being set, options can be modified and canceled (see ”Modifying parameters and deleting LUs” on page 88). 6. To execute pair option change requests quickly, select the Use Time-Saving Model check box above the Pair Settings Parameter list (Change Pair Option). 7. Click Apply on the Continuous Access XP main pane to change options for specified pairs. 8. In the Continuous Access XP main pane, verify that the pair option change completed successfully.
4. Monitor the progress of initial copy operations and status of pairs on the Pair Operation tab of the Continuous Access XP main pane. Refresh the tab as needed. When the status changes from COPY to PAIR, the P-VOL and S-VOL are identical and synchronized. 5. If you are not using RAID Manager commands and host software to complete the migration, use the following procedure to stop using P-VOLs and switch to S-VOLs: a. Stop all host updates to P-VOLs. b.
and RCU mark all cylinders of all suspended Continuous Access XP volumes as modified, so the MCU performs the equivalent of an entire initial copy operation when the pairs are resumed. (The S-VOL cylinder map is used for Continuous Access XP Async operations and Continuous Access XP S-VOL write enable option.) Planned outage of MCUs A planned MCU outage does not affect Continuous Access XP Synchronous.
Major steps in preparing for disaster recovery are: 1. Identify volumes and volume groups containing important files and data for disaster recovery. In addition to supporting Continuous Access XP remote copy operations as well as RAID Manager commands, the disk array provides battery-backed nonvolatile duplexed cache, full hardware redundancy, dynamic sparing, and an advanced RAID-5 implementation to ensure full data integrity if a sudden power outage or other failure occurs. 2.
Data. When S-VOL Data is selected, the P-VOL is fenced if an update copy operation fails. This P-VOL fence level setting ensures that the S-VOL remains identical to the P-VOL after the Continuous Access XP volume pair is synchronized, but makes the P-VOL inaccessible for updates whenever Continuous Access XP remote copy operations fail. This setting should be considered for the most critical volumes for disaster recovery.
File and database recovery procedures When a Continuous Access XP Synchronous pair is suspended, or when the MCU fails due to a disaster, the S-VOL might contain in-process data. A data set could be open or transactions might not have completed. Even if you use the S-VOL Data fence level for all Continuous Access XP Sync pairs, you must establish file recovery procedures. These procedures should be the same as those used for recovering volumes that become inaccessible due to control unit failure.
CAUTION: After an S-VOL changes to simplex, you cannot distinguish it from a non-Continuous Access XP simplex volume. The Continuous Access XP Async C/T is also discarded when the pair is deleted. 5. If necessary, use the logical volume manager to change volume labels of S-VOLs. 6. Ensure that all required file recovery procedures are complete before varying S-VOLs online. 7. At this point, start critical applications at the remote site with previous S-VOLs taking the place of their P-VOLs.
information transferred via host failover software or comparing contents of the S-VOL with other files confirmed to be current (such as database log files). These S-VOLs should be recovered using files confirmed to be current. Remember that the Continuous Access XP Async time-stamp and C/T information indicates MCU service processor time, not host system time. NOTE: Actual data recovery must be done using recovery point data in the database redo log.
8. At the remote site, establish the same Continuous Access XP Async groups and Continuous Access XP pairs in the reverse direction to synchronize the original P-VOLs with the S-VOLs. From the Paircreate parameter pane, select Entire Volume for the Initial Copy field for the Initial copy parameters option. Resuming normal operations at primary sites After Continuous Access XP pairs are established in the reverse direction, you are ready to resume normal operations at the primary (main) site.
Pinned track recovery for Continuous Access XP volumes If a pinned track occurs on a Continuous Access XP P-VOL or S-VOL, the MCU suspends the pair (SIM reference code = DB1x). To ensure full data integrity of the volume pair while recovering the pinned track, use the following procedure: 1. Connect to the MCU of the Continuous Access XP pair containing the volume with the pinned track, and select the correct CU image. 2.
Index A Add CT Group pane 77 Async Option 80 Asynchronous Operation pane 54 audience, documentation 9 B BC, combining with Continuous Access XP 41 C cache inflow control 22 requirements 32 size 86 Cache LUN, combining with other applications 39 Change Pair Option command 102 combining Continuous Access XP with other operations 39 Command View XP management station 18 components 14 configuration operations 60 consistency groups adding 77 defined 16 deleting 79, 82 options 23, 78 parameters, modifying 81 re
ESCON connections components for 15 configuring 37 distances supported 17 requirements 35 system requirements 31 F failover, host 18, 107 fence level 93, 106 Fibre Channel ports components for 14 configuring 37 direct connection 35 distances supported 17, 34 extender connection 35 initiator 18 RCU path parameters 70 switch connection 35 system requirements 31 fibre remote copy connections 34 file recovery 108 firmware versions 9 functions 47 H hardware installation 33 help, obtaining 10, 11 History Operat
SMPL 25 suspending 27 Paircreate command 90 Pairdisplay command 89 Pairresync command 97 Pairsplit-r command 94 Pairsplit-S command 99 PDUB 25, 27, 32, 49 pinned tracks 112 Point-in-Time (PiT) copies 104 Port list 54 Port tree 54 ports initiator 18, 61 local (LCPs) 18 prioritized 40 remote control (RCPs) 18 system requirements 31 target 18, 61 tree and list 54 powering off components 104 preparing for pair operations 87 prerequisites 9 Prioritized Port Control 40 PSUE pair status 25, 26 status icons 49 susp
shared Continuous Access XP/BC volumes 41 sidefile threshold 23, 80 SIMs (Service Information Messages) 111 SMPL pair status 25, 49 Pairsplit-S command 99 S-VOL consistency 110 S-VOL currency 109 SNMP trap 111 split types 27 splitting with pairsplit-r command 94 SSIDs, adding/deleting for RCUs 73 starting Continuous Access XP 46 statistics, Usage Monitor 82 status icons 49 RCU 62 Subscriber’s choice, HP 11 subsystem settings 59 suspend types 29 Suspending status 49 S-VOLs Change Pair Option command 102 cons
