Fixing changes to SnapMirror elements

Accidental deletion of SnapMirror snapshots

SnapMirror snapshots stored on either the SnapMirror source or destination location must not be deleted.

If the base snapshot (most recent common snapshot) is accidentally deleted from either the source or destination location, attempt recovery as follows:

You might be able to recover without reinitializing the destination by breaking the SnapMirror relationship and then resynchronizing the source and the destination.

As long as there is at least one snapshot common to both the source and the destination, resynchronization will succeed. See the section on the snapmirror break command in Converting a destination to a writable volume or qtree and the section on the snapmirror resync command in Resynchronizing a SnapMirror relationship.

If there is no snapshot common to both the source and the destination, you need to use the snapmirror initialize command over the network. Or, if the source and destination are volumes, use the snapmirror store command to store the source volume on tape and then use the snapmirror retrieve command to restore the volume from the tape to the destination.

If you change a destination volume name

If you change the name of a SnapMirror destination volume, you need to manually correct the SnapMirror relationships affected by the change. SnapMirror will be unable to replicate source volume data to a newly-named destination volume whose configuration information is incomplete.

In the case below, the destination, volJobak, was renamed to volStatbak. After the renaming, the snapmirror status command does not show the source. Instead the entry is shown with a '-' appears in the source column.

filerB> vol rename volJobak volStatbak

volJbak renamed to volStatbak

you may need to update /etc/exports

filerB> snapmirror status volJobak

Snapmirror is on.

filerB>snapmirror status volStatbak

Snapmirror is on.

Source        Destination         State          Lag        Status

-             filerB:volStatbak   Snapmirrored   -00:03:22  Idle

If you change the volume name of a SnapMirror source or destination, you need to make the following changes:

Update the snapmirror.conf file, if there is an old entry.
Use the snapmirror release command to update the old destination name, so SnapMirror will release the softlock and the old snapshot.
Use the snapmirror update command on the new volume name, so status registry is updated with the new volume name.
Update the /etc/exports file.
Caution
If a filer is running at its limit of concurrent transfers, and you attempt to initiate more transfers through manual snapmirror update command, the filer can panic. When this particular panic case is triggered, the system log will contain the message "snapmirror: unexpected need to notify a waiting process in replica_unconfigure".