It is possible to preserve snapshots and migrate data, but it's tedious at best and unpractical at worst, it just depends on your data.
You can use ndmpcopy or qtree SnapMirror (I prefer QSM if you have it). But basically you start with the oldest snapshot you want to keep. Migrate that snapshot for each qtree you want to migrate (or I suppose you can just do the volume if you are doing ndmpcopy). Then take a local snapshot on the destination flex vol (probably with the same name).
Repeat this process with each snapshot you want to preserve. Basically,
I think I have the idea but let me repeat it. Let's assume that my volume, call it, vol2, has two filesystems: A and .snapshot. Under .snapshot, I have three snapshots: oldest, old, latest.
I start out by ndmpcopy the oldest: ndmpcopy -da -sa source:/vol/vol2/.snapshot/oldest/A destination/vol/vol2
Then, I take a snapshot on the destination: snap create oldest
Next, I do old: ndmpcopy -da -sa source:/vol/vol2/.snapshot/old/A destination:/vol/vol2 snap create old
Finally, latest: ndmpcopy -da -sa source:/vol/vol2/.snapshot/latest/A destination:/vol/vol2 snap create latest.
Then, I proceed to do a level 0 ndmpcopy of vol2 ndmpcopy -da -sa source:/vol/vol2 destination:/vol/vol2
Michael Homa Operating Systems Support and Database Group Academic Computing and Communication Center University of Illinois at Chicago email: mhoma@uic.edu
you are building them from the ground up. It works, but like I said, it's tedious for most and impossible for some.
Another alternative for those who don't want to go through this process is to just copy the active filesystem over using anything you want, then keep the older disks around until they would have been deleted anyway. Not sure how that would work with your manual snapshots, but some sites with time-based snapshots have found that to be more practical, even if a bit inconvient, for a few weeks/months.
Hope this helps.
-- Adam Fox adamfox@netapp.com
-----Original Message----- From: Michael Homa [mailto:mhoma@uic.edu] Sent: Monday, June 05, 2006 3:51 PM To: toasters@mathworks.com Subject: Suggestions regarding migration from 740 to 270
Hi:
Recently, we elected to replace our primary 740 (we have two) with a 270. The 740, running 6.4.5, has traditional volumes whereas the 270, running 7.0.4, has flex volumes. I'm using ndmpcopy to migrate volumes from the old box to the new. My question concerns snapshots. I was told that I can't use ndmpcopy to migrate the snapshot (if that's not true, feel free to tell me). Anyway, we have some user-created snapshots that hold important changes. I'm looking for suggestions on getting the information contained in the snapshots migrated.
Thanks
Michael Homa Operating Systems Support and Database Group Academic Computing and Communication Center University of Illinois at Chicago email: mhoma@uic.edu