Re: Backup using only one CPU - SA wants to know why

From: Sandra Becker <sbecker6925_at_gmail.com>
Date: Mon, 12 Nov 2012 13:56:27 -0700
Message-ID: <CAJzM94CdJbOx6V+ZR+BRUtXSV+nZuJ=UP-eK7Vqf-XjDX1X2CA_at_mail.gmail.com>

I have a hunch it's something along those lines, but don't know how to prove it. My SA insists there's a setting in the database to "turn on multiple CPUs". If it already recognizes there are 5 of them, I'm not sure what else I can do.
Sandy

On Mon, Nov 12, 2012 at 1:53 PM, <Christopher.Taylor2_at_parallon.net> wrote:

> According to my AIX admin (on a similar question I asked him about active
> sessions) he said its because of the way IBM does CPU scheduling.
>
> I wish I had more info on that.
>
> Chris
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
> On Behalf Of Sandra Becker
> Sent: Monday, November 12, 2012 1:39 PM
> To: oracle-l
> Subject: Backup using only one CPU - SA wants to know why
>
> Oracle 11.2.0.2
> SLES11 on IBM mainframe
> DB size - just below 1T
> I run an incremental 0 backup on my production OLTP once a week,
> incrementals the rest of the week. Recently changed the disk_asynch_io to
> TRUE and the filesystemio_options to SETALL, per recommendations from
> Oracle. I then added a channel to the backup scripts so it uses 4
> channels. These changes shaved 35 pecent off the time it takes to run the
> incr0 backup, which I am very happy with.
>
> The SA monitoring the performance of the mainframe says the incremental 0
> backup of our production OLTP is pegging a single CPU, out of 5 available.
> He thinks the backup would run even faster if it used more CPUs and
> suggested setting the PARALLELISM parameter to more than 1. Unbeknownst to
> him, it had been set to 3 for the past 6 years. He wants to know why the
> backup isn't using more CPUs. Any ideas/suggestions?
>
> --
> Sandy
> Transzap, Inc.
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

-- 
Sandy
Transzap, Inc.


--
http://www.freelists.org/webpage/oracle-l

Received on Mon Nov 12 2012 - 21:56:27 CET