From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nagilum Subject: Re: 4-disk raid5 with 2 disks going bad: best way to proceed? Date: Fri, 08 Apr 2011 17:47:30 +0200 Message-ID: <20110408174730.19073csbt29o450k@cakebox.homeunix.net> References: <20110407221334.16604ufejmh3q9s0@cakebox.homeunix.net> <20110408220528.40971e55@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2; DelSp="Yes"; format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110408220528.40971e55@notabene.brown> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: rob pfile , linux-raid@vger.kernel.org List-Id: linux-raid.ids ----- Message from neilb@suse.de --------- From: NeilBrown Subject: Re: 4-disk raid5 with 2 disks going bad: best way to proceed? > On Thu, 07 Apr 2011 22:13:34 +0200 Nagilum wrote: > >> Hmm, I think you could: >> - add a disk, >> - reshape your raid5 to raid6 while using the layout where the raid5 >> disks aren't really changed > > That would be > mdadm --grow /dev/md0 --level=6 --parity=preserve > (I think). > >> - let it finish syncing >> - reshape the raid6 to raid5 taking one of the bad disks out > > I don't think that makes sense. (what command would you use exactly?) I was thinking one fails one of the bad disks and then does something like: mdadm --grow /dev/md0 --level=5 --raid-devices=4 --backup-file=/root/backup-md4 But obviously I've never tried that and I would play around with losetup and some files for practice and to see if that works before starting. ----- End message from neilb@suse.de ----- ======================================================================== # _ __ _ __ http://www.nagilum.org/ \n icq://69646724 # # / |/ /__ ____ _(_) /_ ____ _ nagilum@nagilum.org \n +491776461165 # # / / _ `/ _ `/ / / // / ' \ Amiga (68k/PPC): AOS/NetBSD/Linux # # /_/|_/\_,_/\_, /_/_/\_,_/_/_/_/ Mac (PPC): MacOS-X / NetBSD /Linux # # /___/ x86: FreeBSD/Linux/Solaris/Win2k ARM9: EPOC EV6 # ======================================================================== ---------------------------------------------------------------- cakebox.homeunix.net - all the machine one needs..