>> On Tue, 28 Mar 2006 11:32:19 +1000, Steven Harris <[EMAIL PROTECTED]> said:
> Here is one way to do a gradual migration. Superb advice. I'd suggest one embellishment: Set up the new primary stgpools, and the new-primary->new-copy housekeeping at the outset (step 2) . Then, set the old-primary stgpools to have RECLAIMSTGPOOLS of the corresponding new-primary. This takes one usually very heavy use of tape drives, and contributes its' efforts to the migration. It introduces the possibility that something might get written to old-primary, and then reclaimed to new-primary before it gets copied to old-copy, but that doesn't seem particularly likely, and the data in new-primary -will- get copied to new-copy. > 1. Set up your new library and devclasses to use it. > 2. set up a new set of copypools parallel to your old set of copypools, and > run backup stg commands on all your primary pools until the copypools on the > new library are up to date - this may take weeks, depending on how much data > is to be copied, but can be stopped and restarted as necessary. Change > housekeeping to copy new data to both new and old copypools. If you are > using 5.3 parallel processing commands watch for the limit of 16 parallel > commands at once. > 3. Once the copypools are caught up, you can change your housekeeping to > stop copying data to the old copypools. > 4. create a new set of primary pools to parallel your old setup. Change > your diskpools to migrate to the new primary pools. Change your > managementclasses that go straight to tape to point to the new primary > pools. Change your housekeeping to backup the new primary pools to the new > copypools. > 5. Make the nextstg of each of the old primary pools to be its new > equivalent. Run migration on the old pools to move the data off to the new > pools. The new migrate stg command with a duration will drip feed this over > time. > 6. Finally, when everything is copied, run del vol on each of the old > copypool volumes (discardd=yes will be needed) and any old primary pool > volumes (discardd=no) that need it, and clean up old definitions. - Allen S. Rout
