HP P6000 Continuous Access Implementation Guide (T3680-96431, August 2012)

Planning for a disaster
Planning helps to minimize downtime caused by a disaster. When planning for disaster recovery,
include the following:
• Ensure that you have a supported disaster-tolerant solution.
NOTE: Not all supported cable configurations will provide for dual fabrics and ISLs.
• Have at least one management server available at every site in case of a hardware or
communication failure.
• Verify that each destination virtual disk within a DR group has been presented to a host. This
allows the host access to the virtual disk immediately after a failover.
• Ensure that local and remote hosts have the latest patches, virus protection, HP Storage System
Scripting Utility, and multipathing software versions for the specific operating system.
• Keep your configuration current and documented at all sites. Install the latest versions of
controller software, HP P6000 Command View, and HP P6000 Replication Solutions Manager.
• Keep a record of your virtual disks, DR groups, and host volume and volume group names.
Capture the configuration information after each significant change or at scheduled intervals.
See “Backing up replication configuration” (page 126).
• Keep HP P6000 Replication Solutions Manager on every management server up-to-date with
configuration changes. See the HP P6000 Replication Solutions Manager online help for the
procedure for exporting and importing the HP P6000 Replication Solutions Manager database.
• Back up the HP P6000 Replication Solutions Manager database. It contains managed set and
job information that you can restore on another management server if necessary.
• Practice the recovery plan. Ensure that everyone in your storage administration is prepared
for disaster recovery. Practice different failure scenarios and make decisions ahead of time.
For example, if a controller fails, is it more important not to disrupt processing by doing a
planned failover, or not to be at risk for a second controller failure that requires an unplanned
failover? In the case of multiple sites, which site has precedence for troubleshooting? Simulated
disaster recoveries are a good way to verify that your records are up-to-date and that all
required patches are installed.
Failover and recovery procedures
The failover procedure depends on the severity of the failure or the reason for the failover. For
example, the procedure for a planned failover applies to anticipated power disruptions, scheduled
equipment maintenance at the local site, or a need to transfer operations to another array. Another
procedure applies to unplanned events such as multiple controller failures, multiple host failures,
or an unplanned power outage at the local site.
You may decide not to fail over in some situations. For example, if only one component fails, you
can repair that component and avoid failing over an entire DR group. In the event of a data center
failure, or if you are planning downtime with a local array, failing over to the remote array can
ensure minimal interruption of data access.
IMPORTANT: Always verify that all components of the remote array are 100% operational
before you fail over.
NOTE: HP recommends that you not fail over any DR group more than once every 15 minutes.
Planning for a disaster 103