Veritas says to create a different filesystem for Full and Incrementals,
due to the backup sizes generally involved and how many files have to
get deleted for each when cleaning a DSSU. Future versions of NetBackup
sound like they'll do a much better job of handling staging disks. 

Some light reading for you:
http://seer.support.veritas.com/docs/270101.htm
http://seer.support.veritas.com/docs/270079.htm
http://seer.support.veritas.com/docs/268777.htm
http://seer.support.veritas.com/docs/265305.htm
http://seer.support.veritas.com/docs/278169.htm
http://seer.support.veritas.com/docs/273532.htm

Depending on what you're using for back-end storage, EMC also has a pair
of whitepapers/briefs you can get on running backups to disk. They
should be available from their webpage somewhere. 
"Effective Write Bandwidth with CLARiiON ATA Disk Drives and RAID 3:
Backup-to=Disk and Streaming Media" 
"EMC Backup Storage Solutions: Backup-to-Disk Guide with VERITAS
NetBackup"

Have fun. =) 
- John Nardello
"Your backups are only as good as your restores."



-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf Of Ed Wilts
Sent: Friday, December 16, 2005 10:51 AM
To: Johnson, Eric K
Cc: veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Disk volume layout question


On Fri, Dec 16, 2005 at 12:52:05PM -0500, Johnson, Eric K wrote:
> We are in the early stages of migrating from Legato NetWorker to
Veritas
> NetBackup 5.1. As part of our migration, we are adding enough disk
space
> to hold one week worth of backups before they are staged to tape.
> 
> When configuring our disk (approximately 9.6TB before RAID in a Sun
> StorEdge 3511 SATA array. NetBackup server is a Sun E450 running
Solaris
> 10) are there any recommendations for how it should be separated out
> into volumes?
> 
> Is it better to have one large volume? Many small volumes? What are
the
> advantages and disadvantages to the given volume sizes from a
NetBackup
> perspective?

With 5.1, a job will fail if the DSSU fills up.  There are no mechanisms
to throw a bunch of volumes at it and let NetBackup chose.  With 6.0,
this problem is supposed to go away.

For now, I'd think that you would want to create a single large array.

All of this assumes that all backups are created equally.  If there is
some stuff that you need to guarantee stays on disk for a week, you may
need to set up individual DSSUs for that stuff (we're doing this for
some Oracle databases).

        .../Ed

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org
_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu