Operating System Software User Manual

Figure 66 Failing Over to the Synchronous Backup System
Follow these failover and recovery guidelines to recover from system failure.
Failover in SLD Remote-Copy Configuration
1. Reverse the role of all volume groups on the synchronous backup system (the failover system).
On the failover system (SystemB), issue the following command:
# setrcopygroup failover -f -t <target_name>
where <target_name> represents the name of the target system that failed (for example,
SystemA).
The setrcopygroup failover -f -t command:
• Changes all secondary volume groups on the failover system (multi.1.r96 on SystemB)
to primary volume groups, and therefore reverses the direction of data replication.
• Enables I/O to the reversed volume groups (multi.1.r96 on SystemB).
• Starts all volume groups on the asynchronous periodic backup system (SystemC).
• Makes the synchronous backup system (SystemB) the temporary primary storage system.
• Sends any newer data—in other words, data that was sent to the synchronous backup
system (SystemB) since the last synchronization between the primary and synchronous
backup system, and before the primary system failed—to the asynchronous periodic
backup system (SystemC).
NOTE: If you do not want to perform disaster recovery operations on all volume groups on
a system, you can use all of the disaster recovery commands on one or more specified volume
groups. For more information, see the description of each command in “About the Remote-Copy
Commands” (page 261).
2. Verify that failover tasks complete successfully (failover of individual groups can still fail).
For example, failing over to the synchronous backup system (SystemB) results in a task list that
looks like the following:
# setrcopygroup failovoer -f -t SystemA
failover started with tasks: 5745
208 Disaster Recovery for SLD Configurations