RE: Backup using only one CPU - SA wants to know why
- From: <Christopher.Taylor2@xxxxxxxxxxxx>
- To: <sbecker6925@xxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 12 Nov 2012 14:53:25 -0600
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@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] 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.
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