Joe - we had this problem for a while and after some investigation we  
tweaked MAX_STAGING_JOBS to "1" so a DSSU would only relocate to one  
drive at any time.

More info in this TechNote http://seer.support.veritas.com/docs/ 
280398.htm.

Rgds,

Henry

On 17 Nov 2006, at 16:03, Joe Royer wrote:

> On a similar note, I created a 1-drive STU for destaging because the
> DSSU has an annoying (and stupid) habit of allocating all available
> drives when it tries to destage.  Of course this makes all the streams
> (3 in this case) go slowly because they're all reading from the same
> DSSU spindles.  The 1-drive STU doesn't work.  I can't help noticing
> that the option says "Maximum concurrent drives used for backup"  (not
> duplication).  This must be a bug since it defeats the whole purpose
> of the DSSU, which is to keep the tape drive spinning.  5.1 MP5 Linux
> (haven't tried it on MP4 yet).
>
>
> ----Original message----
> Date: Thu, 16 Nov 2006 06:13:22 -0500
> From: "Bobby Williams" <bobbyrjw at bellsouth.net>
> Subject: Re: [Veritas-bu] Duplications running very slow
>
> There was a known problem in 5.1 with duplication within the same  
> storage
> unit.
>
> Just to see if this is hurting you (I have done this at my 18  
> different NB
> sites), create a new storage unit in your library called  
> "duplication".
> Make it 1 drive, on demand only.  (you don't have to lessen the  
> number of
> concurrent drives in you other storage unit).
>
> Try a duplication (manual or vault) and pick "duplication" as the
> destination storage unit.
>
> See if things speed up.
>
>
> Bobby Williams
> 2205 Peterson Drive
> Chattanooga, Tennessee  37421
> 423-296-8200
>
>
> -- 
> Joe Royer / SysAdmin / Digital Motorworks / 512-692-1028
>
>
> This message and any attachments are intended only for the use of  
> the addressee and may contain information that is privileged and  
> confidential. If the reader of the message is not the intended  
> recipient or an authorized representative of the intended  
> recipient, you are hereby notified that any dissemination of this  
> communication is strictly prohibited. If you have received this  
> communication in error, please notify us immediately by e-mail and  
> delete the message and any attachments from your system.
> _______________________________________________
> Veritas-bu maillist  -  Veritas-bu at mailman.eng.auburn.edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu





-------------- next part --------------
An HTML attachment was scrubbed...
URL: 
http://mailman.eng.auburn.edu/pipermail/veritas-bu/attachments/20061117/124c9004/attachment.html