Hi
I assume that you are saying that a given backup runs much faster or slower
at different times.
I also assume that you are talking about dlt tape drives.
One thing that can cause a difference is speeds is a marginal tape drive or
marginal tapes.
The dlt drive will retry failing i/o and can work after many retrys, and the
backup software will not see an error. You may get the cleaning light
turned on. Maybe not.
Your ce can dump the error logs stored in the drive, which includes soft
errors.
len
----- Original Message -----
From: <nitin.jog AT abnamro DOT com>
To: <veritas-bu AT mailman.eng.auburn DOT edu>
Sent: Tuesday, November 04, 2003 6:27 PM
Subject: [Veritas-bu] Peculiar slowdown in Veritas netbackup.
> Hi,
>
> I am using netbackup v34_5 on HPUX 11i. The master is connected to an STK
> DLT tape library with 4 drives and robotic arm.
> I have 2 backups, one is a 73GB backup for oracle database(at filesystem
> level). The other is approx 40GB backup
> (again filesystem based).
> The backend is EMC storage.
>
> I have setup the netbackup tuning parameters NUMBER_DATA_BUFFERS = 16
> SIZE_DATA_BUFFERS=65536.
>
> This is the problem:
> I am getting inconsistent timings on the backups when run simultaenously.
> (individual times are fine). These are only 2 backups that run on this
> server.
> On a good day, I can finish both the backups running simultaenously in
> around 3hours.
> (2.5 hours for 73GB) and (1.5 hours for 40GB)
>
> but quite a few times the 2nd backup takes 4hours..its just
sluggish..there
> is not much I/O going through. Even if the first backup finishes (in 2.5
> hours) the second backup continues to stay sluggish. We dont see any disk
> contention, the netbackup is also tuned to the best of knowledge, there is
> no high cpu usage, there is ample memory 4GB, so what else could cause
> this behaviour ?
>
> really appreciate any clues..have a case open with veritas also.
>
> Thank you
> Nitin
> --------------------------------------------------------------------------
-
> This message (including any attachments) is confidential and may be
> privileged. If you have received it by mistake please notify the sender by
> return e-mail and delete this message from your system. Any unauthorised
> use or dissemination of this message in whole or in part is strictly
> prohibited. Please note that e-mails are susceptible to change.
> ABN AMRO Bank N.V. (including its group companies) shall not be liable for
> the improper or incomplete transmission of the information contained in
> this communication nor for any delay in its receipt or damage to your
> system. ABN AMRO Bank N.V. (or its group companies) does not guarantee
that
> the integrity of this communication has been maintained nor that this
> communication is free of viruses, interceptions or interference.
> --------------------------------------------------------------------------
-
>
>
>
>
> _______________________________________________
> Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
>
|
