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Enterprise applications

Manual failover

Contributors jfsinmsp
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The term "failover" does not refer to the direction of replication with SnapMirror active sync because it is a bidirectional replication technology. Instead, 'failover' refers to which storage system will be the preferred site in the event of failure.

For example, you may want to perform a failover to change the preferred site before you shut down a site for maintenance, or before performing a DR test.

Changing the preferred site requires a simple operation. IO will pause for a second or two as authority over replication behavior switches between clusters, but IO is otherwise unaffected.

GUI example:

SystemManager clip of SM-as preferred site

Example of changing it back via the CLI:

Cluster2::> snapmirror failover start -destination-path jfs_as2:/cg/jfsAA
[Job 9575] Job is queued: SnapMirror failover for destination "jfs_as2:/cg/jfsAA                      ".

Cluster2::> snapmirror failover show

Source    Destination                                          Error
Path      Path        Type     Status    start-time end-time   Reason
-------- -----------  -------- --------- ---------- ---------- ----------
jfs_as1:/cg/jfsAA
         jfs_as2:/cg/jfsAA
                      planned  completed 9/11/2024  9/11/2024
                                         09:29:22   09:29:32

The new destination path can be verified as follows:


Cluster1::> snapmirror show -destination-path jfs_as1:/cg/jfsAA

                            Source Path: jfs_as2:/cg/jfsAA
                       Destination Path: jfs_as1:/cg/jfsAA
                      Relationship Type: XDP
                Relationship Group Type: consistencygroup
                 SnapMirror Policy Type: automated-failover-duplex
                      SnapMirror Policy: AutomatedFailOverDuplex
                            Tries Limit: -
                           Mirror State: Snapmirrored
                    Relationship Status: InSync