HP P4000 Multi-Site HA/DR Solution Pack User Guide Abstract This guide contains detailed instructions for designing and implementing the Multi-Site SAN features of the HP P4000 SAN Solution. The Multi-Site SAN features enable you to synchronously and automatically mirror data between geographic sites. Topics include designs for network configurations and instructions about implementing the network designs. The intended audience is system administrators who manage HP P4000 SAN solutions.
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Contents 1 Designing a Multi-Site SAN.........................................................................4 Failover Manager overview........................................................................................................4 Requirements...........................................................................................................................4 Designing a Multi-Site SAN........................................................................................................
1 Designing a Multi-Site SAN The Multi-Site SAN features enable you to synchronously mirror data between sites automatically. You create a Multi-Site SAN by configuring equal numbers of storage systems into sites in the software.
Data center failures • Site power outage • Site network outage • Site disaster (fire, flood, terrorist attack, and so forth) Individual storage system failures • Power outage • Network outage • System disaster • System failure (backplane, motherboard, RAM, CPU) Configuring data replication for optimal availability and redundancy The SAN/iQ software offers six levels of synchronous replication at a volume level.
Figure 1 Sample configuration for two-site, data protection level Network RAID-10+2 1. Volumes are configured with Network RAID-10+2 Configuring sites and quorum managers to achieve optimal high availability and redundancy Several recommended site configurations can be used with the Multi-Site SAN software. These configurations provide varying levels of availability and redundancy. “Common configurations of Multi-Site SANs and mangers” (page 7) shows the recommended configurations.
In addition to setting up the Multi-Site clusters for data replication, it is important to set up the SAN managers for quorum correctly to ensure that in the event of a failure the system can be properly recovered. Maintaining quorum can be either an automated process or manually recovered by an Administrator. Table 2 (page 7) summarizes common Multi-Site SAN and manager configurations.
Figure 2 Three physical sites: cluster spans two sites, Failover Manager in third site 1. Volumes are configured with Network RAID-10 Figure 3 Two physical sites, logical third site: cluster spans two sites, Failover Manager in logical third site 1.
Figure 4 Three physical sites: cluster spans three sites 1. Volumes are configured with Network RAID-10+1 Figure 5 Two physical sites: cluster spans two sites, one site is the primary site 1. Volumes are configured with Network RAID-10 Alternative setups The Multi-Site SAN software supports many other valid configurations than the four illustrated in the prior section.“Alternative Multi-Site SAN configurations ” (page 10) lists other possible configurations.
Table 3 Alternative Multi-Site SAN configurations Alternate configuration Description Details More than one Multi-Site cluster in the management group Multiple clusters running within the The Multi-Site SAN software supports running same management group. many clusters in the same management group. You simply need to make sure that clusters have the same number of storage systems in each site for that particular cluster. More than three sites There are more than three sites in the cluster.
• • Assign servers to sites—Avoid high-latency connections by assigning application servers to the site where the server is located. Application servers assigned to a site connect only to storage systems in the same site as follows: ◦ Without MPIO—With servers set up in the CMC with the load balancing option, the system sets up the iSCSI session only to storage systems assigned to the same site.
Figure 6 Dual redundant links between two sites 1. Dual redundant GigE links Figure 7 Dual redundant links between two sites with Failover Manager in logical third site 1. Dual redundant GigE links 2.
Figure 8 Triangular network with Failover Manager 1. Dual redundant GigE links Figure 9 Hub and spoke network core with redundant links out to each site 1.
Figure 10 Combination full-mesh core with triangular links to all sites 1. Full mesh core network Using multiple subnets You can use multiple subnets with a Multi-Site SAN. Multiple subnets let you have multiple VIPs, one VIP per subnet. The advantage of using multiple VIPs is that you can connect to a volume without having to leave the local subnet. Alternatively, you can assign an application server to a site. Application servers assigned to a site connect only to storage systems in the same site.
Figure 11 Multi-Site SAN mapping to subnets, VIPs, and application servers 1. Dual redundant GigE links Connecting volumes to multiple subnets in a Multi-Site SAN using the Microsoft iSCSI initiator Connecting to volumes in a multiple subnet configuration is similar to connecting to volumes in a single-site configuration, with the following important differences: • You must configure all cluster VIPs for discovery, for proper failover/failback configuration of a Multi-Site SAN.
Figure 12 Entering VIPs in a Multi-Site SAN configuration 2. 3. 4. On the Targets tab, select the volume to log on to. Click Log On. Select the Enable multi-path check box if using MPIO. Figure 13 Logging on to volume 5. 6. 7. 16 [Optional] If you want this volume to be available after rebooting, select the Automatically restore... check box. Click Advanced to open the Advanced Settings window. Configure the Advanced Settings as follows: • For Local adaptor, select Microsoft iSCSI initiator.
Figure 14 Target portal value remains Default 8. After setting the values, click OK to close the Advanced Settings dialog. 9. Click OK again to finish logging on. 10. If you want to set the MPIO load balancing policy, see the HP P4000 DSM for MPIO Deployment Guide. 11. If you have multiple NICs, repeat steps 1 through 10 for the additional NICs.
Using the Primary Site designation in two-site configurations The Multi-Site SAN software supports designating a particular site as Primary so that it does not go offline when the secondary site goes offline, or when the network link between sites goes offline.
Table 6 Common Multi-Site SAN configurations with recommended managers Multi-Site SAN configuration Manager configuration Two physical sites, one site is primary For four storage systems, run: • two managers in the primary site • one manager in the secondary site For six storage systems or more, run: Number of managers and number Needed to maintain quorum • Manager count = three Number for quorum = two • Manager count = five Number for quorum = three • three managers in the primary site • two managers i
2 Implementing a Multi-Site SAN After you have designed the Multi-Site SAN configuration, you are ready to implement it. Before you begin Install Multi-Site SAN feature keys on the storage systems you are going to use. Register your storage systems. For more information, see “Registering Advanced Features” in the HP P4000 SAN Solution User Guide for information about registering your storage systems.
Figure 15 Using the management group wizard to create a Multi-Site SAN NOTE: You must have at least one storage system for each site in the Available Systems pool before starting. Creating the management group The first part of the wizard creates the management group, which includes configuring the optimal number of managers for the initial setup.
Creating sites When creating a new site, you first create the site and then assign storage systems to that site: 1. Click New to open the New Site window. 2. Enter a name for the site and an optional description. 3. [Optional] Make the site primary, if appropriate. 4. 5. Click Add in the Site Systems section and then select the storage systems for this site. Click OK when you have finished creating the site.
Figure 17 Viewing the Sites Details tab window Converting an existing SAN to a Multi-Site SAN Plan the conversion according to the criteria described in “Preparing to convert an existing SAN to a Multi-Site SAN” (page 20). Prerequisites • Upgrade all storage systems to SAN/iQ software version 7.0 or later. • Obtain the feature keys for storage systems to be used in the Multi-Site cluster. • Apply the feature keys to the storage systems.
10. Assign one or more VIPs as planned for your site layout, and then click Next. The Create Volume window opens with the Skip Volume Creation box checked. If you want to create a new volume for your Multi-Site cluster, clear the box and fill in the volume information. 11. Click Next to complete the wizard. 12. Verify the settings for the sites you have just configured. 13. Click Close when you finish reviewing the Summary information.
Best practice Install the Failover Manager on a server in a separate physical location from the SAN sites, and then add it as a separate site in the management group. Doing so will prevent loss of quorum in a site failure, regardless of which single site fails. Adding the Failover Manager to the management group and site Adding the Failover Manager to the management group will likely cause the manager configuration to become less than optimal.
Viewing sites in the CMC To view sites in the CMC, select the Sites node in the navigation window. The Sites node is displayed in every management group. Typically, however, the Sites Details tab shows the storage systems as unassigned. The site designation has no effect outside of the Multi-Site SAN configuration. Figure 18 No sites in a standard cluster When there is a Multi-Site cluster in the management group, the Sites Details tab shows the site assignments of the storage systems and servers.
• Sites • Sites (Grouped) Designating a primary site Use the Primary designation when you are using the Multi-Site cluster to maintain a primary site and a second site as a backup site. Designate the site as Primary when you create the site, or you can edit an existing site to make it primary. Only one site can be designated as Primary in a Multi-Site cluster. Make sure that the majority of managers are in the Primary site.
1. 2. Select the Sites node in the navigation window. Select the site you want to delete in the Details tab, right-click, and then select Delete Site. NOTE: If only one site will be left in the cluster, the warning shown in “Deleting a site that contains a storage system causes this warning” (page 28) is displayed. Figure 20 Deleting a site that contains a storage system causes this warning 3. Click OK to delete the site.
Removing storage systems from a Multi-Site cluster Removing storage systems from a Multi-Site cluster affects the capacity of the cluster and the Multi-Site configuration. • Ensure that the capacity remaining after you remove the storage system(s) is sufficient for the data on the volumes. • To maintain the Multi-Site configuration, plan to remove equal numbers of storage systems from each site. To remove the storage systems from the site 1. 2. 3. 4. Select the Sites node in the navigation window.
3 Support and other resources Contacting HP For worldwide technical support information, see the HP support website: http://www.hp.
New and changed information in this edition The following additions and changes have been made for this edition: • The following information has been updated: ◦ • P4000 SAN Solution software and user manuals have been rebranded Functionality has been added that allows adding servers to sites.
Glossary The following glossary provides definitions of terms used in the SAN/iQ software and the HP P4000 SAN Solution. acting primary volume The remote volume, when it assumes the role of the primary volume in a failover scenario. Active-Passive A type of network bonding which, in the event of a NIC failure, causes the logical interface to use another NIC in the bond until the preferred NIC resumes operation. At that point, data transfer resumes on the preferred NIC.
DSM Device Specific Module. DSM for MPIO The HP P4000 DSM for MPIO vendor-specific DSM that interfaces with the Microsoft MPIO framework. failback After failover, the process by which you restore the primary volume and turn the acting primary back into a remote volume. failover The process by which the user transfers operation of the application server over to the remote volume. This can be a manual operation, a scripted operation, or VMware enabled.
Multi-Site cluster A cluster of storage that spans multiple sites (up to three). A Multi-Site cluster must meet at least one of the following conditions: • Contain storage systems that reside in two or more sites • Contain storage systems that span subnets • Contain multiple VIPs. The cluster can have a single site, and the multiple VIPs make it a multi-site cluster. network RAID Synchronous replication, mirroring or parity protection on a volume-by-volume basis.
RAID status Condition of RAID on the storage system: • Normal - RAID is synchronized and running. No action is required. • Rebuild - A new disk has been inserted in a drive bay and RAID is currently rebuilding. No action is required. • Degraded - RAID is not functioning properly. Either a disk needs to be replaced or a replacement disk has been inserted in a drive. • Off - Data cannot be stored on the storage system. The storage system is offline and flashes red in the network window.
shared snapshot Shared snapshots occur when a clone point is created from a newer snapshot that has older snapshots below it in the tree. All the volumes created from the clone point will display these older snapshots that they share, as well as the clone point. site A user-designated location in which storage systems are installed. Multi-Site SAN configurations have multiple sites with storage systems in each site, and each site has its own subnet.
volume set Two or more volumes used by an application. For example, you may set up Exchange to use two volumes to support a StorageGroup: one for mailbox data and one for logs. Those two volumes make a volume set. volume size The size of the virtual device communicated to the operating system and the applications. VSS Provider HP P4000 VSS Provider is the hardware provider that supports the Volume Shadow Copy Service on the HP P4000 SAN Solution.
Index Symbols 2-site configurations primary site designation in, 18 A adding additional capacity to existing sites, 28 site, 27 storage systems to Multi-Site cluster, 28 alternative Multi-Site SAN configurations, 9 application clusters setting up in a Multi-Site SAN environment, 17 application server connecting to Multi-Site SAN, 17 application servers assigning to sites, 11 B benefits of a Multi-Site SAN, 4 best practices failover manager, 11 implementing Multi-Site SAN network, 10 installing Failover Ma
configuring for high availability and redundancy, 6 configuring for Multi-Site SAN, 24 configuring regular, 24 failover, for Multi-Site SAN, 4 failover, in typical 3rd site configuration, 7 overview, 24 map view for sites, 26 MPIO and multiple subnets, 17 Multi-Site cluster creating, 21 removing storage systems from, 29 wizard, 23 Multi-Site SAN alternative configurations, 9 common configurations with recommended Failover Manager, 18 common network designs, 11 converting from an existing SAN, 23 designing,
volumes creating with Multi-Site SAN wizard, 21 W websites HP, 31 HP Subscriber's Choice for Business, 30 product manuals, 31 wizard, Multi-Site clusters, 21 40 Index
