ADSM-L

Re: backup stgpool

2005-09-08 14:01:30
Subject: Re: backup stgpool
From: Sandra <sadi AT SUPER.NET DOT PK>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 8 Sep 2005 23:05:19 +0500
Welll Andrew,
I had misconception as under:
1- backup stgpool will backup entire primary storagepool daily with DB tape.
This would be one set and on disaster, this set will recover us to the point
where that DB stands.

2- If any data tape in above set gets corrupted, i have a choice of going back
one step for earlier set of DR tapes. This way i presumed that DBexpire and plan
expire  would give me 4 sets of "DB and data" to recover to.

Now my understanding is:
1- DB tapes along with plan file would decide which tapes in DR set are
required.

Now confusion is:
1- What would happen if one of my data tapes required by certain DB and plan
file gets corrupted, since backup stgpool has incremental backup, that file
might not be recoverable leading to entire restore failure.

2- WOULD the DB expire, planfile expire and reuse delay of 4 make me to do full
backup of stgpool on 5th day? or what??

Another insight by Todd is also making good sense to me and i am following his
point too and is also probably one of the solutions to my problem. but my above
confusions still remain the same.

Can anyone please enlighten me on this?

Kind Regards
Sandra


Andrew Raibeck wrote:

> > Ok..i have to have two copy storage pools both having a complete and
> > separate set of tapes. From this i understand that everytime the
> > stgpool backup is performed, there is no way to tell TSM that you
> > need to take full backup of primary pool instead of incremental from
> > what it did last day.
>
> That is correct.
>
> Why would you want to do otherwise?
>
> 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
> 23:21:02:
>
> > Hmmm thanks andy,
> > I have changed the reuse delay to 4, that is the same as dbbackup
> > expiration days.
> >
> > Ok..i have to have two copy storage pools both having a complete and
> > separate set of tapes. From this i understand that everytime the
> > stgpool backup is performed, there is no way to tell TSM that you
> > need to take full backup of primary pool instead of incremental from
> > what it did last day.
> >
> > Kind Regards
> > Sandra
> >
> >  ---- storman AT US.IBM DOT COM wrote :
> > > 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
> > > >
> > > >
> > > >
> > > >  _____________________________________________________
> > > >  Sent via SUPERwebmail - Supernet web-based email service
> > > >  http://www.super.net.pk/mail
> > >
> > >
> >
> >
> >  _____________________________________________________
> >  Sent via SUPERwebmail - Supernet web-based email service
> >  http://www.super.net.pk/mail

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