Re: Questions on ASM best practices

From: Ls Cheng <>
Date: Tue, 16 Dec 2014 17:23:05 +0100
Message-ID: <>


You can create two disk groups, data and fra and place one member in each disk group

Regarding a ew disk groups per DB. I only do that when I have to snapshot the disks, seperate each DB in their own disk groups otherwise just use a couple of disk groups.


On Tue, Dec 16, 2014 at 4:17 PM, Hameed, Amir <> wrote:
> Hi folks,
> I am in the process of implementing ASM for the first time. I have a few
> questions that I would like to ask regarding ASM best practices for both
> single instance and RAC databases. The Grid/ASM version is
> · Redo log file placement – In the non-ASM world, I am used to
> using two groups for redo logs on multiple mount points with multiple log
> members in each group. How does this change in ASM? For an
> externally-managed ASM disk group, should there be multiple ASM redo disk
> groups with each hosting a redo log group or should one ASM redo disk group
> with multiple members be sufficient?
> · Managing multiple databases – In the non-ASM world, we allocate
> a separate set of mount points for each database that we set up. This
> isolates an environment at the storage level and also enables us to take
> storage-based snapshots of a database file systems for backup. Restore is
> also simple and quick where we restore from the online snaps. What is the
> best approach to manage multiple databases in ASM? Should each DB have its
> own set of ASM disk groups or should all databases be placed in the same
> set of disk groups? For example, for databases with SIDs ABCD, MNOP & WXYZ:
> o Should there be only one set of ASM disk group (DATA, REDO, RECO,
> etc.) for all of the above databases OR
> o Should ABCD be in its own set of disk group (DATA_ABCD, REDO_ABCD,
> RECO_ABCO), WXYZ be in its set of disk group (DATA_WXYZ, REDO_ WXYZ, RECO_
> WXYZ), etc.? This model seems to give more flexibility in terms of retiring
> an environment where a DG could just be dropped and a new one created when
> setting up a new environment, either via cloning or creating one from
> scratch.
> · AU and stripe sizes – For an Oracle E-Business Suite type
> system, which is hybrid in nature, should the AU size be 1M for the DATA
> and REDO groups? Should the stripe size be 1M and 128k for DATA and REDO
> groups respectively?
> Any feedback will be appreciated.
> Thanks,
> Amir

Received on Tue Dec 16 2014 - 17:23:05 CET

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