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Re: Hard Disk selections

From: Chris Dunscombe <>
Date: Thu, 22 Sep 2005 07:39:57 +0100
Message-ID: <>


One simple point you should consider:

Assume you currently have 10 * 76 GB disks and keeping the same capacity with 146 GB you'll now have 5 * 146 GB disks. This means you have 1/2 the number of spindles to cope with the I/O load. This may cause you a big performance problem especially if your current disks are more than 30% busy due to I/O. If however they are < 15% then you'll probably be OK.

HTH Chris

Quoting Bryan Wells <>:

> Let me apologize in advance if i leave any good facts out and have to
> restate...
> I am in process of migrating an existing windows 2k,
><>test environment to some beefier hardware
> attached to IBM FastT SAN (?). The
> current environment is a Dell Poweredge 6400 p3 4x500 MHz/ with internal and
> external disk being 76GB 15k RAID 5. The new environment will be a blade
> with 2x2.5Ghz, at least, attached to the san. My question; will performance,
> Oracle that is, suffer going with a bigger disk (146Gb) on the SAN, or
> should I stay with the 76GB disk? The requirement is to not allow the
> performance to degrade below the existing SLA, however, we will have more
> users hitting this test instance once the cut over has been made. Because
> the hardware will not be over 4+ years old, my gut feel is that the bigger
> disk should not be an issue in this type of environment any more than that
> seen with the 76Gb in the existing environment, however, how do I prove
> this?
> Any links to help Green DBA Man understand Oracle and disk selections?
> As always, thanks for your help and patience.
> --
> Bryan Wells
> Oracle DBA hopeful

Chris Dunscombe

Received on Thu Sep 22 2005 - 01:42:14 CDT

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