Re: Oracle Disk Configuration question.

From: Howard J. Rogers <hjr_at_dizwell.com>
Date: Thu, 3 Jun 2004 08:44:08 +1000
Message-ID: <40be5825$0$1588$afc38c87@news.optusnet.com.au>

"Michael Austin" <maustin_at_firstdbasource.com> wrote in message news:jvovc.2120$tC7.2072_at_newssvr23.news.prodigy.com...

[snip]

> But then again, you also must consider your controllers
> and drives. Using HP EVA or Hitachi technology with 146GB-309GB fibre
> drives and many GB of cache, many of the concerns of RAID5 dissipate
> into oblivion.

No they don't, actually. If you read Cary Millsapp's paper at www.baarf.com ("Is RAID 5 Really a Bargain") you'll see that practically none of the concerns can disappear into oblivion, because they are intrinsic to RAID-5, however implemented and with whatever lovely piece of technology you care to name. The write penalty is only one of the major concerns with RAID-5. Cost, lack of flexibility, woeful failure performance, and increased risk of failure compared to RAID-1 are some of the others. Your (expensive) GB of cache might make the write penalty issue go away, but it can't send the others off into oblivion.

Regards
HJR Received on Wed Jun 02 2004 - 17:44:08 CDT