Re: ASM and RAID

From: Robert Klemme <>
Date: Wed, 17 Dec 2008 02:55:36 -0800 (PST)
Message-ID: <>

On Dec 17, 10:11 am, AlexB <> wrote:
> While not being a very large database shop, all I can say about ASM on top of
> RAID is that it uses extra CPU, but makes DBA life a bit easier (no need to
> specify datafile names and easier to create new instances, for example). We are
> using IBM DS4000 series SAN with RAID10 LUNs presented (through VIO server) to
> AIX/Linux LPARs on a pSeries 570. AIX LPARs are using direct access to raw
> devices by Oracle 9iR2 processes, while Oracle 10gR2 on Linux uses ASM. If we
> look at 'sar' output - we can hardly notice the overhead (our CPUs are 1.65GHz
> POWER5), while looking at nmon/topas screens during data loads or queries we can
> see ASM processes taking some 7-10% of CPU at peak times. Did not encounter any
> reliability matters so far.

This is in line with an article I recently stumbled across:


robert Received on Wed Dec 17 2008 - 04:55:36 CST

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