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Re: Oracle on EMC Clarion CX500

From: Paul Drake <>
Date: Tue, 5 Apr 2005 15:29:34 -0400
Message-ID: <>


I haven't worked with that particular unit, but have worked with a CX200 and CX600.

Multipath (duplicate FCHBAs, duplicate FC switches).

8 disk RAID 10 LUNs with a 1 MB stripe works great for datafiles. you'll be amazed at how fast your rman backups will fly. you'll likely want a finer-grained volume (less disks, smaller RAID stripe size) for online redo logs and controlfiles.

Match your filesystem block size to the oracle file blocksize.

Don't share filesystems with datafiles, backup sets and archived redo logs.

if you're using filesystems, divide each LUN in half, the first half for live files, the second half for backup sets (or leave dark). Ideally, no other app will be accessing your physical hard drives.

If you don't know your data access paterns ... you're just guessing. If you are performing entirely single block IOs and there isn't good locality of data, larger stripes and read-ahead are not going to help. data dictionary performance views (and statspack data from these) can assist you in determining physical IO avg blocks per read.

What is your db_block_size?
If you have set your db_file_multiblock_read_count to something like 16, you'll likely want a smaller stripe size for the LUN for datafiles, say 256 KB.

After you migrate to 10g (and gather system stats), you may be able to get away with a larger db_file_multiblock_read_count (without the CBO wanting to tablescan/hash_join everything) in which case a larger stripe size will be better.

I would think that EMC (or even Dell | EMC on the units that they sell) has documentation on this.


On Apr 5, 2005 2:12 PM, Arnon, Yuval <> wrote:
> All,
> We are in the process of moving our DB (oracle on WIN2003 ADV
> SERVER) to a SAN (EMC Clarion CX500) in an NON RAC environment.
> We are interested in getting advice related to best practices regarding
> configuration of the SAN. (i.e.=20
> If you have any experience or know of any good docs on this please let
> us know.
> TIA.
> Yuval.
> This transmission may contain information that is privileged, =
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>, are not the intended recipient, you are hereby =
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> --

#/etc/init.d/init.cssd stop
# f=ma, divide by 1, convert to moles.
Received on Tue Apr 05 2005 - 15:33:48 CDT

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