Backup using only one CPU - SA wants to know why

From: Sandra Becker <sbecker6925_at_gmail.com>
Date: Mon, 12 Nov 2012 12:38:45 -0700
Message-ID: <CAJzM94BG0+tvxHUBQyvq2PYzKGW5rBu23roPZHPiX=tyzR6=1g_at_mail.gmail.com>



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?

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Sandy
Transzap, Inc.

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http://www.freelists.org/webpage/oracle-l Received on Mon Nov 12 2012 - 20:38:45 CET

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