Re: New Disk Setup

From: onedbguru <>
Date: Thu, 28 May 2009 18:16:31 -0700 (PDT)
Message-ID: <>

On May 28, 8:05 pm, joel garry <> wrote:
> On May 28, 1:15 pm, Mark D Powell <> wrote:
> > The fact that RAID-5 only protects you from the loss of a single disk
> > in the stripe is one reason I suggested two 4 disk stripes rather than
> > just a single 8 disk stripe but I have seen places use stripes with
> > over 20 disks in them.  (If a single disk is likely to fail once in
> > 300 years how many disk failures would I expect if I had 300 disks?)
> 300 :-)
> (One time we managed to get a whole SAN worth of bogus disks - from
> IBM, no less.  IIRC, they sold that division to Hitachi.)
> jg
> --
> is bogus.
> Bing it on:

If all 8 drives are dedicated to database files (not software) then, and the size of 4 devices is sufficient (lets be conservative and say you need 1TB of storage and you have 8 256GB drives, then I would use ASM and create 2 disk groups and put both of them in a failure group.

Disk 1-4 on controllerA
Disk 5-8 on controllerB
ASM Diskgroup AA = disk 1-4
ASM Diskgroup BB = disk 5-8
ASM FAILURE GROUP 1 = AA,BB This will provide striping, failover and some modest performance.

Use ASM [CORRECTLY] and you won't regret it - coming from someone that has used it for a multi-hundredTB database and lets just say we added more data/day than most of these small db's in their lifetime... Received on Thu May 28 2009 - 20:16:31 CDT

Original text of this message