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

From: Martin Klier <>
Date: Mon, 12 Nov 2012 21:52:26 +0100
Message-ID: <>


two questions:
You opened multiple channels. Is it possible to write to them concurrently? Often SBT media disallows that and breaks the parallelism. Silly, but necessary: Do you have Enterprise Edition?


Sandra Becker schrieb:
> Oracle
> 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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Received on Mon Nov 12 2012 - 21:52:26 CET

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