Re: ASM question !

From: Hans Forbrich <>
Date: Wed, 28 Nov 2012 12:12:16 -0700
Message-ID: <>

On 28/11/2012 10:58 AM, John Hallas wrote:
> Does RAC have to be on ASM? Not checked the docs fully but I am surprised you cannot still not use shared filesystems if you wish. I am not advocating not using ASM but I did not think it was mandatory yet
RAC for EE just needs to use a shared (cluster aware) file system.

The challenge is finding a reliable cluster aware file system. There are several available, but you need to look.

One major issue for me is that most file systems (and file system administrators) only think in terms of OS files - many small files - which contradicts the requirements of large databases - few, but large, files.

Another issue is that most storage administrators will argue, without understanding the needs of databases, that RAID 5 or 6 is the right way to go for databases (search for "Silent corruption in RAID 5"), that SAN mirroring is better than sliced bread, and that block-based striping is more suitable than AU/file-based striping. Which is fine by me - I just ask them to sign an agreement that states they take full responsibility for decisions and consequences related to storage. (Who knows, they might be right.)

But if I had my druthers, I'd go for NetApp (or ZFS Appliance) and dNFS.

For 11g, Oracle has desupported using RAW devices for new databases. (


Received on Wed Nov 28 2012 - 20:12:16 CET

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