Overview of Manual Failover Steps When Backup Group Leader Is Unreachable
When the group leader cannot reach the backup group leader, it transitions to
out of sync. You can use either the array OS GUI or the CLI to confirm that the backup
group leader is unavailable:
- The Hardware page in the array OS GUI displays a red asterisk next to the backup group leader.
- The CLI command group --info |grep -i <group leader> reports that the backup group leader is unreachable.
Before you begin the manual takeover, make sure there is a common snapshot between the two arrays in the group. The common snapshot simplifies the process of re-enabling synchronous replication.
To perform a manual failover when the backup group leader is not available, you
must complete the following high-level steps:
- Disassociate the downstream volume from the volume collection
and remove synchronous replication. This will allow host connections. You can use the array OS CLI commands to remove the downstream partner from the volume collection schedules.NOTE: You can re-enable synchronous replication after you complete the manual takeover and the group leader and backup group leader are in-sync again.
For information on performing this task, see the section Remove Synchronous Replication from the Downstream Partner in the CLI Administration Guide.
- Bring the downstream volume online as a non-synchronous
replication volume. When you disassociate the downstream volume and bring it
online this way, the following happens:
-
Existing ACLs from the upstream volume are cloned to the downstream volume.
- The LUNs on the downstream volume get new numbers.
- A new iSCSI serial number is assigned to the downstream volume.
- The downstream volume is no longer listed as a downstream volume in the GUI.
-
- (Optional) When the group leader and the backup group leader are both online and in-sync again, set up synchronous replication again.
- Perform a handover operation.