[Veritas-bu] Re: Fast backup to tape but slow backup to disk on NBU

2005-08-22 15:08:32
Subject: [Veritas-bu] Re: Fast backup to tape but slow backup to disk on NBU
From: kfhemness AT ucdavis DOT edu (Kathryn Hemness)
Date: Mon, 22 Aug 2005 12:08:32 -0700 (PDT)
Hi Matt --

I have a Fibre Channel SATA and over 260 backups to run every night so
I have my concurrent jobs set to 24.  However, because I can't stage diskimages
to tape while active backups are writing to the disks, I have to
run a daily script to alternate the active storage unit for my backup

I'd vote for SCSI at this point.

> Message: 5
> Date: Mon, 22 Aug 2005 14:17:43 -0400
> From: Matt Clausen <mclausen AT csit.fsu DOT edu>
> Organization: Florida State University
> To: "'Veritas List'" <veritas-bu AT mailman.eng.auburn DOT edu>
> Subject: Re: [Veritas-bu] Fast backup to tape but slow backup to disk on NBU
>  5.1MP3
> Matt Clausen wrote:
> > This has indeed been a very valuable thread to me.... and I've
> > implemented a bunch of the suggestions given so far and will have some
> > results to send back to the list in a little while...
> Well, here's the final setups that seem to be working for me now....
> First off, there is a lot of conflicting information out there on the
> net, where some people say to do it one way and someone else says
> something totally in the opposite direction... So while this may work
> for me, it might not work for you all that well.... That being said...
> I had a 16x250GB SATA Array which originally I had setup as a single 16
> disk RAID5 unit. I fragmented this array up into 3 5-disk RAID3 groups
> with only 1 LUN (the 16th disk is a global spare).
> Then using Veritas Volume Manager, I striped the LUNs together into a 3
> disk 256k stripe RAID0 set and put a Veritas File System on there.
> Under Netbackup I made it so only ONE job goes to this disk at a time.
> As someone mentioned, SATA is good at sequential writes not random
> writes so when one job goes at a time, I am seeing 10-15Kb/sec transfers
> (still not what I would expect for a disk based backup but better then
> what I was seeing).
> It'd be interesting to see if a Fibre Channel to SATA setup would be
> better then the SCSI to SATA based one I am using right now.. or if a
> straight up SCSI based solution would offer better performance.
> --__--__--