From mboxrd@z Thu Jan 1 00:00:00 1970 From: Turbo Fredriksson Subject: Re: RAID-6 ... Date: Mon, 17 Jan 2005 09:04:07 +0100 Message-ID: <877jmcwkg8.fsf@pumba.bayour.com> References: <200501101713.j0AHDx922062@www.watkins-home.com> <16869.55531.489452.193862@cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: (Gordon Henderson's message of "Sat, 15 Jan 2005 16:12:12 +0000 (GMT)") Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids >>>>> "Gordon" == Gordon Henderson writes: Gordon> On Thu, 13 Jan 2005, Neil Brown wrote: >> There is no current support for raid6 in any 2.4 kernel and I >> am not aware of anyone planning such support. Assume it is 2.6 >> only. Gordon> How "real-life" tested is RAID-6 so-far? Anyone using it Gordon> in anger on a production server? I've been using it for a couple of months (3 or 4 if I'm not mistaken) on my SPARC64 (Sun Blade 1000 - 2xSPARC III/750) with (four+two)*9Gb disks which gives me 16Gb disks pace. With this setup (I had a few 9Gb disks that I couldn't/wouldn't use for anything else) four (4!) disks can fail without it matter... Have worked flawlessly even though the disks are OLD - 'smartctl' shows that almost all of the disks have had more than 28000 hours 'uptime' (i.e. 'powered on'). That's more than 3 years (POWERED ON mind you!). Granted, I've been 'fortunate' (?!) to have had NO disk crashes etc, but I did simulate a few when I sat the system up and it worked just fine... Kernel 2.6.8.1 (with a couple of patches to get it to boot/work on SPARC64). If it works this great on a SPARC64 (with which the kernel have problems with), then it should work just FINE on a ia32... Gordon> Can it be considered more or less stable than RAID-5? For me (NOTE!!) I'd say "just as stable". But naturally this (should/could) depend on the exact kernel version in use... If a kernel version works this/that good, stick with it... Gordon> Should I stick to my RAID-5 on-top of RAID-1 pairs? In theory, that would be "more secure/safe" since both RAID5 and RAID1 is better tested, but... -- Soviet genetic SEAL Team 6 FSF nitrate Honduras $400 million in gold bullion Albanian Kennedy Ft. Meade DES fissionable Uzi quiche kibo [See http://www.aclu.org/echelonwatch/index.html for more about this]