Re: choosing the right RAID level for PostgresQL database

From: Greg Smith <greg(at)2ndquadrant(dot)com>
To: sergey <sergey(dot)on(dot)net(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: choosing the right RAID level for PostgresQL database
Date: 2011-02-13 23:23:19
Message-ID: 4D5867E7.1090409@2ndquadrant.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

sergey wrote:
> I got a disk array appliance of 8 disks 1T each (UltraStor RS8IP4). It
> will be used solely by PostgresQL database and I am trying to choose
> the best RAID level for it.
> ..
> Space is the least important factor. Even 1T will be enough.

Use RAID10, measure the speed of the whole array using the bonnie++ ZCAV
tool, and only use the fastest part of each array to store the important
stuff. You will improve worst-case performance in both sequential reads
and seek time that way. Drives are nearly twice as fast at their
beginning as they are at the end, and with only 8 drives you should be
able to setup a RAID10 array with all the fast parts aligned.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Mark Rostron 2011-02-14 01:29:51 comparison of 8.3.10 to 8.3.14 reveals unexpected difference in explain plan
Previous Message Scott Marlowe 2011-02-13 22:59:25 Re: choosing the right RAID level for PostgresQL database