From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stan Hoeppner Subject: Re: Suboptimal raid6 linear read speed Date: Wed, 16 Jan 2013 14:29:43 -0600 Message-ID: <50F70DB7.6020104@hardwarefreak.com> References: <20130115123301.GA11948@rabbit.us> <50F55046.7050605@turmel.org> <20130115125507.GA12184@rabbit.us> <50F614F7.20104@hardwarefreak.com> <20130116025857.GA31112@rabbit.us> Reply-To: stan@hardwarefreak.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130116025857.GA31112@rabbit.us> Sender: linux-raid-owner@vger.kernel.org To: Peter Rabbitson Cc: Phil Turmel , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 1/15/2013 8:58 PM, Peter Rabbitson wrote: > On Tue, Jan 15, 2013 at 08:48:23PM -0600, Stan Hoeppner wrote: >> With only 4 drives RAID6 doesn't make sense as RAID10 is superior in >> every way. > > Except raid6 can lose any random 2 drives, while raid10 can't. This isn't a legitimate argument. The probability of you being struck by lightning is greater than two drives in the same mirror in a 4 drive RAID10 dying before a rebuild completes. I challenge you to do an exhaustive search for anyone, at any time in history, who was managing the array properly, suffering such a two drive failure and losing a RAID10 array, 4 drives or greater. Note that controller failures with all drives on one controller don't count, as that failure mode will take down any array of any RAID level. -- Stan