[dba-Tech] Performance in disc partitions

Since you mentioned the RAID thing I might as well add that as soon as you
put stuff on RAID that advantage may go away.  Raid takes over and puts
stuff where it will on the disks under its care.  It might very well create
the first volume on the edge, who knows.  OTOH it might not.   


John W. Colby
Colby Consulting
www.ColbyConsulting.com 
-----Original Message-----
From: dba-tech-bounces at databaseadvisors.com
[mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of DJK(John)
Robinson
Sent: Monday, January 28, 2008 9:24 AM
To: 'Discussion of Hardware and Software issues'
Subject: Re: [dba-Tech] Performance in disc partitions

Well, I've trawled the web, and come up with the usual bunch of conflicting,
unsubstantiated tosh.  My favorite was along the lines of "running RAID 1
completely eliminates the need for backup".  Yeah, right.  Step away from my
system, sir.

The consensus, though, is that the first partition goes next to the edge,
with the last one by the spindle.  People differ in saying what difference
this makes - a lot or hardly any:
http://partition.radified.com/partitioning_2.htm
http://www.xsibase.com/forum/index.php?board=15;action=display;threadid=3452
8 

I found PassMark Performance Test (30-day free trial) at
http://www.passmark.com/products/pt.htm;  I've no idea how good it is
generally

I tried this on first and last partitions on a 500GB disc and got results
suggesting 25%-45% better performance on the *first* partition, which
supports the 'edge is first is better' theory.  I'm not publishing the
results, because they weren't on a scientific basis, but I *am* going to put
my active stuff first, near the edge, and my dormant stuff last!

John