From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: New raid level suggestion. Date: Thu, 30 Dec 2010 11:58:12 +0000 Message-ID: <4D1C73D4.6050600@anonymous.org.uk> References: <20101230082356.GC2986@bitwizard.nl> <4D1C470E.4080406@crc.id.au> <20101230094230.GE2986@bitwizard.nl> <4D1C616D.8030904@hardwarefreak.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D1C616D.8030904@hardwarefreak.com> Sender: linux-raid-owner@vger.kernel.org To: Stan Hoeppner Cc: Linux RAID List-Id: linux-raid.ids On 30/12/2010 10:39, Stan Hoeppner wrote: [...] > Any RAID scheme that uses parity is less than optimal, and up to > horrible, for heavy random IO loads. As always, this depends on "how > heavy" the load is. For up to a few hundred constant IOPS you can get > away with parity RAID schemes. If you need a few thousand or many > thousand IOPS, better stay away from parity RAID. Sorry, I have to disagree with this, in this situation. RAID-6 over 4 discs will be just as fast for reading multiple small files as RAID-10 over 4 discs, and a web server is a read-mostly environment, while at the same time I can't imagine any RAID schema ever giving thousands of IOPS over 4 discs, parity or no. Cheers, John.