[Veritas-bu] Odd tape drive problem
Dale_Kramer at steris.com
Tue Mar 19 11:20:41 CST 2002
Here's a good one. Running NB 3.4, Solaris 2.6 master and media server.
DLT7000 tape drives in an STK9714.
Our backups on one media server were running slow. I watched the tape
drives using sar -d | grep st to find blocks written, device busy, and
service time. In the beginning of the backup the drives were 100% busy,
about 19000 blocks/sec, with low service times. As the backup continued
the drives remained 100% busy, about 8000 blocks/sec and high service
times. Towards the end of the backup the stats went back to the 19000
blocks/sec. Sometimes backups would just remain at 100% busy, 1000 -
3000 blocks/sec with high service times. There are 4 drives attached to
this media server and they all do the same thing. Nothing has changed.
This all of a sudden started happening. I don't think it's the drives
or the master. I am wondering if it's the communication between the
media and the master during backup. Any ideas?
Dale P. Kramer
Senior Enterprise Systems Analyst
5960 Heisley Rd.
Mentor, OH 44060
When you are standing at the edge of a cliff, a step forward is not
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