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

8. If you plan to operate for an extended time at the remote site and need to enable failsafe
mode on a DR group. Make sure the new destination (previous source) and Fibre Channel
links are functioning, and then perform the following steps:
a. If the DR group is suspended, resume it and wait for the log disk to finish merging.
b. Once the log has finished merging, change the DR group to failsafe mode.
NOTE: You can enable failsafe mode at the destination array during a merge or
normalization.
After resolving the cause of a failover, you have three options:
• Remain failed over on the remote array.
• Return operations to the local array. See “Failback to the original source following a planned
or unplanned failover” (page 110).
• Return operations to new hardware at the local site.
Unplanned failover
Scenario: You have experienced an unplanned loss of the local site or the source array. The duration
of the outage is unknown. The hardware components (for example, hosts, array controllers, and
switches) at the local site may or may not still remain intact.
Action summary: Fail over the destination DR array. When the local site is back online, you can
fail back to the previous source array or to a replacement array. Figure 54 (page 106) shows an
unplanned transfer of operations to a remote site.
When an unplanned site failover occurs when the DR group is in asynchronous mode, the DR
group is put in synchronous mode and a normalization is initiated when the destination array
becomes available. The replication mode returns to asynchronous mode once the normalization
completes.
Procedure:
To resolve an unplanned failover:
1. If you cannot access the management server that is managing the arrays, establish management
control with another management server. For instructions, see the HP P6000 Command View
User Guide.
2. Fail over the DR groups.
Using the HP P6000 Replication Solutions Manager, select the destination DR group, and
then select Actions→Failover. See the online help for additional information.
3. Issue operating system commands to resume host I/O to the new source. See “Resuming host
I/O after failover” (page 118).
After resolving the cause of a failover, you have three options:
• Remain failed over on the remote array.
• Return operations to the local array. See “Failback to the original source following a planned
or unplanned failover” (page 110).
• Return operations to a replacement array at the local site.
Recover from failsafe-locked after destination loss
Scenario: You have experienced an unplanned loss of the remote array or a loss of the connection
to the remote array, due to failure of the ISLs, loss of power at the remote site, loss of remote
switches, and other similar events. The duration of the outage is unknown. The DR groups are
failsafe-locked and host I/O is paused.
108 Failover and recovery