Hi Rick,
TSM does provide a way to make sure the tape matches the DB, even when you
restore the DB to a back level. (Or rather, it makes sure the backups that
should be there, are there.) It's the REUSEDELAY parameter on the storage
pools.
If you set the REUSEDELAY option to 5, tapes that are reclaimed do NOT go
back to EMPTY after reclaim; instead they go into PENDING state for 5 days.
That way you can't make them SCRATCH again until the 5 days are up.
So supposed you restore your DB back 3 days. Your DB is the "map" of your
tapes; now it points to backups where they were 3 days ago, before any
expiration/reclaims took place. But since those reclaimed tapes never went
to scratch, they weren't written over, and what the DB thinks is there, is
still there. (Reclaim doesn't erase any data on the tapes, remember - just
the pointers to it in the DB.)
Now some of your other tapes have additional data appened to them, and some
new tapes have been written on by more recent backups. But since the DB
doesn't know about them, it's as though it never happened.
SO, if you keep DB backups for X days, meaning you think maybe one day you
might need to restore your DB back X days, you better have at least ONE tape
storage pool with REUSEDELAY set to X+1 days.
************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
[EMAIL PROTECTED]
"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
************************************************************************
-----Original Message-----
From: Richard L. Rhodes [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, September 19, 2001 8:06 AM
To: [EMAIL PROTECTED]
Subject: Re: Is there a way to delete all files that were backed up
lastnight for certain clients
On 19 Sep 2001, at 10:35, David Longo wrote:
> That question has come up here about viruses. I don't think there is an
> easy way. Maybe someone has some experience/ideas.
Lets suppose that instead of just a few clients, you wanted to do
this for all clients - or at least be willing to accept loosing all
backups from the previous night . . . . .
Could you restore the db to the previous backup, and if in
rollforware mode, roll forward to before the backups started?
I've often wondered what would happen in this situation because
what's on tape wouldn't match what is in the db. This would be
especially true if migration, expiration, and reclamation have run.
This situation is always true if your db backups are done in normal
mode (NOT using roll-forward). In this case, any db restore will
always leave the db out of sync with what's on tape.
I've never had a good explanation of this situation, and the
documentation is completely silent.
Rick
