RE: asm disks

From: Bobak, Mark <>
Date: Mon, 4 Feb 2013 16:00:56 -0500
Message-ID: <>

I agree with Andrew's opinion. ASM using hardware RAID and only use ASM mirroring if you don't have hardware RAID solution available. And yes, high redundancy for OCR and voting disks, even if on hardware RAID.


-----Original Message-----
From: [] On Behalf Of Andrew Kerber Sent: Monday, February 04, 2013 3:45 PM
Subject: Re: asm disks

ASM has the options of normal redundancy, high redundancy, and external redundancy. Every time I have worked with ASM for database storage I have used external redundancy, which means using the hardware RAID functionality instead of the ASM functionality. I do sometimes use a high redundancy group for the OCR and voting files, in addition to the hardware RAID, since those groups are relatively small.

I guess this is a long winded way of saying most people only use the ASM mirroring if the hardware RAID is unavailable, and I expect that is a best practice, though I do not recall seeing it anywhere.

On Mon, Feb 4, 2013 at 2:37 PM, Mike Hayes <> wrote:

> I haven't done anything with ASM disks. Had a consultant come in to do
> an install on a physical server with it's own set of disks. He was all
> about that ASM was the way to go and to not use hardware raid and just
> let ASM do everything for you was best practice. Now I start reading
> the Storage Administrators guide and come across the following in chapter 2:
> Logical unit numbers (LUNs)шк~sing hardware RAID functionality to
> create LUNs is a recommended approach. Storage hardware RAID 0+1 or
> RAID5, and other RAID configurations, can be provided to ASM as ASM disks.
> It seems to me we have just gone against best practice. For those who
> have experience with ASM do you use hardware raid or not?
> Thanks in advance for your input.
> --

Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'


Received on Mon Feb 04 2013 - 22:00:56 CET

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