Veritas-bu

[Veritas-bu] Volume Pools [recommendations please]

2006-04-26 09:15:10
Subject: [Veritas-bu] Volume Pools [recommendations please]
From: simon.weaver AT astrium.eads DOT net (WEAVER, Simon)
Date: Wed, 26 Apr 2006 14:15:10 +0100
Paul
It may or may not be a problem, but if 1 1/2 tapes are used for a policy
with a 2 week retention and then a 2nd policy comes along and uses the
remainder of that 1/2 tape with a retention of 2 months, that tape cannot be
used until the image expires (at least that is how I see it).

We have Policies that include Full and Incrementals. They are multiplexed
onto several tapes, but Incrementals are set to only multiplex to one tape.

So yes, more tapes, bigger library, but as we backup 10TB of Data, I think
its needed and on top of this, a further 4TB will be added later this year
when we start backing up Unix and More Exchange Servers.

Again, this is all going to be down to each and every environment and how
best to implement Netbackup.
I would say your environment is a lot smaller compared to ours (not really
sure of your setup), but again each Business is going to do things
differently.

Im not sure if there is a misunderstanding here, but to put it again I have
a Policy for each type of Server we have (example AD Servers, DNS Servers,
Exchange, Unix, Mission Critical Clusters, ect).

There are policies where they contain MULTIPLE clients (ie: 50) and share a
single volume pool. I have some cases where 2 policies share the same volume
pools, but in most cases each has a separate volume pool.

And we always have around 40 - 50 scratch tapes available to use. The above
does NOT include Month ends, which most are all in 1 separate policy with
corresponding Volume Pools. Month end tapes are of course removed in a safe.

It works very well, and with the correct multiplexing, we hardly use many
tapes (seeing as we backup so much in a week).

Regards

Simon Weaver
3rd Line Technical Support
Windows Domain Administrator 

EADS Astrium Limited, B32AA IM (DCS)
Anchorage Road, Portsmouth, PO3 5PU

Email: Simon.Weaver AT Astrium-eads DOT net



-----Original Message-----
From: Paul Keating [mailto:pkeating AT bank-banque-canada DOT ca] 
Sent: 26 April 2006 13:51
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Volume Pools [recommendations please]


 
> Paul, note the word "possibly" in my last statement. My
> thought of this was
> 1 volume pool with say 3 tapes. Lets say one policy runs and 
> completes and
> uses 1 1/2 tapes. Later a 2nd policy runs (using the same 
> pool) and possibly
> uses the remainder of the 1/2 tape before starting a new tape.

Uh hunh. Not sure how that's a problem...it makes the most efficient use of
your tapes, otherwise half of your tapes are only half full....requires more
tapes, bigger library (more slots), more media management, more drives (ie.
Tape belonging to a particular policy is in a drive, another policy cannot
start to backup untill a free drive is available to insert it's own tape) I
think the amalgation of volume pools is something that has to be done as
businesses expand from SMB -> Enterprise. We have a business line that used
to do their own "local" backups, and when we went to the Central Entrprise
backup environment, one of their requirements was to have every server
backed up to a spearate tape, that was removed each day, labeled with the
date and server name, signed by the person who removed it, initialed by a
witness, and sealed in an envelope, walked to the other "tower", and palced
in a vault. Obviously that wasn't gonna work....this was a database
application group, and we had to convince them that it was ok to let the
Netbackup database manage the tapes....part of "going big" I guess.

> 
> Volume Pools, in my view should be separate in most cases.
> But each to their
> own.

True..to each their own.
Depends on the environment I suppose. I've got a small environment, (about
4TB in a full backup window) but it sounds a bit bigger than your's. I have
220 physical machines, plus several dozen VMs, in 42 policies (most clients
fall into one of about 10 policies due to retention differences or mandated
media segregation, the rest are one offs for specific filesystems,
application, or whatever.)

If each policy had it's own volume pool, a single night's incremental backup
would probably use every tape in my 219 slot library....the way we are
currently setup, we currently have about 25 scratch tapes, and we haven't
had to add or remove tapes in about 18 months, with 7 volume pools other
than scratch. (including Daily, Weekly, Monthly and Yearly pools...though
I'd like to migrate out of that paradigm.)

Paul

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