You can use "Max_Jobs_Per_client" as a global setting (or as a
per-client setting I think is "Max_jobs_this_client"). Then you set the
schedule to use multistreaming, and in the schedule you add several
clients. 
Several streams, but one client at a time will kick in the tape.

-.SebaS.-


-----Original Message-----
From: Weber, Philip [mailto:Philip.Weber AT egg DOT com] 
Sent: Wednesday, September 15, 2004 6:36 AM
To: 'veritas-bu AT mailman.eng.auburn DOT edu'
Subject: [Veritas-bu] Multiplexing Question

Hi all,

During ongoing performance investigations I'm coming to the conclusion
that
in our environment single-streaming with multiplexing gives us better
performance than multi-streaming with multiplexing.  The individual
client
backups may take longer but the overall usage of the tape drives is
better.

Two reasons for this :
1. Most of the clients are on 100/mb interfaces & aren't able to supply
multiple streams fast enough concurrently.
2. When multiple streams are multiplexed, typically multiple streams
from
the same client go to the same tape drive, so a slow client will really
drag
the tape drive throughput down.

My question is, whether I can set NetBackup up so that with multiplexing
at
the storage unit and schedule level, and multiple streams from each
client,
only one stream from any one client will go to any one tape drive?  i.e.
one
stream per client per drive, but multiple streams possible from one
client
across the robot.  I think this would be an optimal compromise but don't
at
present think it can be done.

Not sure if I've explained this very well...!?

regards, Phil

Phil Weber
Egg UNIX Technologist
Phone: 01384 26 4136
Mobile: 


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