From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Nelson Subject: Re: unbelievably bad performance: 2.6.27.37 and raid6 Date: Mon, 2 Nov 2009 13:39:35 -0600 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org Cc: LinuxRaid List-Id: linux-raid.ids On Sat, Oct 31, 2009 at 1:59 PM, Christian Pernegger wrote: >> md0 : active raid6 sda4[0] sdc4[5] sdd4[4] sdb4[6] >> =A0 =A0 =A0613409536 blocks super 1.1 level 6, 64k chunk, algorithm = 2 [4/4] [UUUU] > > Why would you use a 4 disk raid6? If 50% of raw capacity is enough > just go with raid10 With 4 disks, the ability to sustain *any two* devices going bad is a b= ig bonus. Using raid10 with two copies (1 original, 1 duplicate) on 4 disks gives me 50% space but I can only sustain *1* failed device. I'm guessing I'd have to go with raid10 with three copies (1 original, 2 duplicate) which is even worse (2/3 space lost). Did I just calculate that all wrong? --=20 Jon -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html