echo 262144 > /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS will increase
tape buffer size to 256K

-mike

-----Original Message-----
From: Gajda, Michael [IT] [mailto:michael.gajda AT ssmb DOT com]
Sent: Wednesday, March 21, 2001 2:42 PM
To: 'veritas-bu AT mailman.eng.auburn DOT edu'
Subject: [Veritas-bu] Increasing NetBackup Tape Block Size


Is there a way to increase the size of the tape blocks that NetBackup
(3.4.1) writes?  I am trying to improve the performance of an STK 9840 tape
drive connected via fibre to a SAN.  Using NetBackup (and my test data) I
was only able to achieve backups at the rate of 6.5MB/sec.  

I got similar results using GNU tar and the default block size of 64KB, but
when I increased the block size to 256KB I backed up the same data at the
rate of 12MB/sec.  

NetBackup uses a block size of 64KB.

****************************************************************
Michael Gajda                 michael.gajda AT ssmb DOT com                
Salomon Smith Barney    Dasd Management/Vital Records
745 Route 3                    phone: 201-231-3408   
Rutherford, NJ 07070       


_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu