ADSM-L

Re: backup stgpool

2005-09-08 02:09:32
Subject: Re: backup stgpool
From: Andrew Raibeck <storman AT US.IBM DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 7 Sep 2005 23:09:41 -0700
Hi Sandra,

I'm sure you'll get plenty of advice and suggestions from others, but here
are my "two cents":

Once concern right off the bat is the reuse delay of zero, which puts at
risk your goal of 100% restore capability of up to 4 days ago. Instead,
your reuse delay should be the same as your dbbackup and plan file
expiration settings. Consider the case where on day 1, tape 'A' contains
valid data that is expired on day 2. Tape 'A' is now empty, so it is
available for immediate reuse. On day 3, the tape is written over with new
data. Now it is day 4, and you need to restore your database back to day
1. You restore the database back to day 1. Now you want to restore data
from tape 'A' that was there on day 1... but that data no longer exists
because it was written over with new data on day 3... and your 100%
restore capability is out the window.

>From what you wrote, I am under the impression that you think you need
multiple sets of copy storage pools to allow you to restore up to 4 days
ago. But this is not true. Since each copy pool is a logical mirror of the
primary pools, a single copy pool is all that is necessary to restore your
data up to four days ago (assuming everything else is also configured to
minimally meet the four day requirement). If you want an onsite copy pool
and an offsite copy pool, then have two copy pools: one that stays onsite,
and another that goes offsite. You can then run BACKUP STGPOOL multiple
times to back up the primary pools to each of your copy pools. If you need
more onsite copy pools, you can define them and back up the storage pools
to them.

Regards,

Andy

Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Development
Internal Notes e-mail: Andrew Raibeck/Tucson/IBM@IBMUS
Internet e-mail: storman AT us.ibm DOT com

The only dumb question is the one that goes unasked.
The command line is your friend.
"Good enough" is the enemy of excellence.

"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 2005-09-07
21:41:21:

> Dear All,
> I am running TSM 5.2.3 on Windows 2003 with 3582 Library with 2
> drives. Ultrium2 tapes with 200GB space.
>
> Daily incremental backup of about 5GB.
>
> I have setup a copypool to which i backup my primary pool daily. The
> plan file (after running prepare) has ever increasing tapes required
> for primary stgpool restore.
>
> My question:
> Can i take full backup of stgpool daily and not the incremental on
> daily basis. The command refernce says it won't copy any file to
> copypool until the file is damaged or not available in copypool...
> that is sort of incremental.
>
> Purpose is to send one set of DR tapes to offsite weekly on friday.
> I want this set to be 100% capable of restoring my environment while
> at the same time, having 3 sets of DR at main site so that I can
> revert to a maximum of 4 days.
>
> DBbackup and plan file expiration is 4 days, and volume reuse delay
> in all stgpools is 0. I want to reuse the tapes immediately.
>
> Can anyone enlighten me on this.
>
> Regards,
> Sandra
>
>
>
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