When you resync or otherwise change the directions of the snapmirrors, a "snapmirror release" will remove the snapmirror tag from the snapshots, but will not remove the snapshots. You should also remove any snapshots on the new source that has a system-id of the new source. I do this everytime a direction changes, both when going into DR mode and when coming out.
George
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Nathan Patwardhan Sent: Monday, October 20, 2008 3:22 PM To: Toasters Subject: Question about SnapMirror, cascade, and deleting old snapshots.
We using SnapMirror for three filers in a cascade. filerA is the master so we normally cascade SnapMirror as filerA->filerB->filerC.
In the case of a DR event, we'll repoint things so we end up with filerB->filerA->filerC or filerC->filerA->filerB or some combination like that. After the DR event is over, we put restructure the cascade so that it goes A->B->C as noted above. As part of this restructuring, we will do a 'snapmirror release' for any relationships that no longer exist after things are repointed. Generally this cleans up any snapshots that we don't need and things are happy.
Recently, I noticed that we have a couple of old and somewhat large snapshots that never expire. These have been around for a couple of months and are hogging 5-10% of a volume that's already pretty full. I'd like to delete them but I don't see any Broken-Off relationships when I run 'snapmirror status <volume>'. I'm just not comfortable winging it with release until I get a better grasp on how SnapMirror got into this state.
Looking at 'snapmirror destinations -s <volume>' I have a pretty good idea of how things were pointed in our cascade during DR events that generated these snapshots in the first place, but I remain unclear about how to (or even if I can!) do a snapmirror release in this case.
Please advise!
-- Nathan Patwardhan "Of course, the US has many elements of socialism already since capitalists, like cats, tend to get themselves stuck up a tree every so often." -- Joe Johnston