How to restore restore SnapShots from SnapMirror remote side?

heightsnj · ‎2016-05-27

If I 7 days SnapShots retention, and SnapMirror is scheduled once per day to remote side along with 7 days SnapShots. Assuming one of Snapshots on the primary site got removed. My question is, what will be steps to restore the Snapshot back from the remote side if there is any?

Thanks for your help!

aborzenkov · ‎2016-05-27

It is not clear - do you ask how to restore content of this snapshot (full or partial) or do you want to literally get snapshot back (I.e., "undelete " it)?

heightsnj · ‎2016-05-28

Lost one day of SnapShot on Primary site, and wanted to restore the entire SnapShot from SnapMirrored DR site back to the primary site.

aborzenkov · ‎2016-05-28

The only way to get snapshot back is to reverse snapmirror direction and completely rewrite source volume. This is rather disruptive procedure.

heightsnj · ‎2016-05-29

Yes, it sounds very disruptinve to the primary volume.

I would not want to make any changes to the production volume on Primary, only a snapshot for a day within 7 days retention. Are you sure there is no any other ways to restore one of snapshots only from DR site not the volume and all 7 days worth snapshots? I am asking because what i am trying to do seems pretty common.

Thanks!

aborzenkov · ‎2016-05-29

No, it is not common, unless there is misunderstanding and you want something else. What is common is to restore volume state to one of snapshots on snapmirror destination, or to restore individual files from it.

heightsnj · ‎2016-05-29

Ok. I am not sure if you understand it. Let's say I need to restore a file in day 3 snapshot, and this snapshot is missing from Primary. Can I then restore the file from day 3 snapshot from DR? when the schedule snapmirror kicks off, the snapmirror will also replicate all local daily SnapShots over to DR, and that's why DR keeps all SnapShots on Primary.

Hope I made myself clear this time.

aborzenkov · ‎2016-05-29

Yes, as long as snapshot is still available on secondary, just make it accessible (over NFS or CIFS, as appropriate) and simply copy file over.