RE: asm disks

From: Mark W. Farnham <>
Date: Mon, 4 Feb 2013 16:31:25 -0500
Message-ID: <020101ce031e$fd1f1d20$f75d5760$>

IF you're talking about actual hardware RAID, then that is definitely preferable in all cases of which I am aware.

IF you're talking about mixing ASM with another software RAID possibly being pushed by the hardware manufacturer, I *think* that is a disadvantage.

-----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
> 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 - 22:31:25 CET

Original text of this message