Path: newssvr20.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!prodigy.com!rip!sjc70.webusenet.com!news.webusenet.com!sn-xit-02!sn-xit-01!sn-post-01!supernews.com!corp.supernews.com!not-for-mail From: Daniel Morgan Newsgroups: comp.databases.oracle.server Subject: Re: Single-disk database and I/O load balancing? Date: Fri, 10 Oct 2003 17:49:25 -0700 Organization: ATS Message-ID: <1065833376.158390@yasure> User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 References:

In-Reply-To: Content-Type: multipart/alternative; boundary="------------010601070202040102090509" Cache-Post-Path: yasure!unknown@pond178.drizzle.com X-Cache: nntpcache 2.4.0b5 (see http://www.nntpcache.org/) X-Complaints-To: abuse@supernews.com Lines: 102 Xref: newssvr20.news.prodigy.com comp.databases.oracle.server:245098 --------------010601070202040102090509 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Geomancer wrote: >>Seriously using one disk for an oracle database is asking for trouble in >>most (all?) production environments. You've no safety margin - if that disk >>fails it's game over (at least whilst you find another disk and reinstall >>from a backup). >> >> > >Thanks Andy. Yes, maybe I should clarify. Of course, the disk is >mirrored (one client is triple mirrored) and all are protected against >disk failure with redundant controllers. > >My issue is cost justification and the "myth" of disk file >segregation! > >When a "single" disk system (a mirrored pair) is large enough to hold >the whole database, how do I justify asking them to buy six more >72-gig spindles "three mirrored disk pairs", just to segregate redo >and indexes and undo. > >Bottom-line, is disk segregation on non-RAID disk really a "myth", or >does it apply to mirrored-only disk databases where the entire >database is under 100 gig? > >By the way, I have checked vendors, and it's hard to find a disk with >less than 72-gig these days. . . > > By discussing performance. If you don't have any performance issues there isn't much of a point as long as you have mirrored redundancy from 0+1 or 1+0. -- Daniel Morgan http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp damorgan@x.washington.edu (replace 'x' with a 'u' to reply) --------------010601070202040102090509 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Geomancer wrote:

Seriously using one disk for an oracle database is asking for trouble in
most (all?) production environments.  You've no safety margin - if that disk
fails it's game over (at least whilst you find another disk and reinstall
from a backup).


Thanks Andy.  Yes, maybe I should clarify.  Of course, the disk is
mirrored (one client is triple mirrored) and all are protected against
disk failure with redundant controllers.

My issue is cost justification and the "myth" of disk file
segregation!

When a "single" disk system (a mirrored pair) is large enough to hold
the whole database, how do I justify asking them to buy six more
72-gig spindles "three mirrored disk pairs", just to segregate redo
and indexes and undo.

Bottom-line, is disk segregation on non-RAID disk really a "myth", or
does it apply to mirrored-only disk databases where the entire
database is under 100 gig?

By the way, I have checked vendors, and it's hard to find a disk with
less than 72-gig these days. . .

By discussing performance. If you don't have any performance issues there isn't much of a point as
long as you have mirrored redundancy from 0+1 or 1+0.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan@x.washington.edu
(replace 'x' with a 'u' to reply)

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