Definitely not, and I can't see it ever happening with SCSI-based tape 
drives.

Your options really come down to:

1.      Tune up the OS and NetBackup in great detail to make certain you 
have the very best you can get from the media servers.

2.      Look closely at how the data is coming to the media servers - if 
they are coming from network backups, consider DSSUs to separate the slow 
network backup from destaging from local disk to tape.  However, make sure 
you use fast disks and tune them up- I've seen reports on this list that 
suggest cheap SATA arrays cannot do this very well.

There are quite a few ways to break down the process of the data getting 
from the client to the tape into separate sections that you can measure 
and tune up.  If you are using UNIX servers Veritas have quite a bit of 
accumulated wisdom on tuning the OS - they just don't seem to publish it, 
and 1st line support don't know it either - but it is there.   There are 
plenty on TCP/IP measuring tools and tuning advice for various kinds of 
NIC.  You can run bpbkar with the -nocont option to see how quickly NBU is 
getting data off the disks.

William D L Brown




"jason" <veritas2-bu AT jasons DOT us> 
Sent by: veritas-bu-admin AT mailman.eng.auburn DOT edu
20-Dec-2005 18:36
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Subject
[Veritas-bu] sharing tape drives







Will NBU6 allow multiple media servers to write to a single tape drive 
simulaneously?  A customer of mine is going to using STK T10000 drives and 

their media servers each can't supply enough data to keep the drive fully 
fed so we're hoping to be able to multiplex that way.

Any other ideas besides making the media servers faster?  Unfortunately 
that's not an option due to a software limitation.

-- 
-Jason

-----
Jason K. Schechner
    --- There are no ABSOLUTE STATEMENTS   I'm very probably wrong. ---
"The difference between genius and stupidity is that genius has its 
limits."
  - Albert Einstein
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