From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Tran Subject: Re: Failed RAID5 Date: Thu, 12 May 2005 09:52:33 -0500 Message-ID: <1115909553.6694.6.camel@langvan2.homenetwork> References: <4283172b.242.630.20549@clanwind.com> <17027.10878.872935.948925@cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17027.10878.872935.948925@cse.unsw.edu.au> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Thu, 2005-05-12 at 05:05, Neil Brown wrote: > On Thursday May 12, janaka@clanwind.com wrote: > > Hey, > > > > I am trying to rebuild a failed raid 5. I have one disk > > that's bad, and one disk that, in the confusion, has become > > convinced that it is a spare. I don't know where it got > > this idea, but I have drive "mdadm --assemble --force > > /dev/md2 /dev/hda3 /dev/hdc3 /dev/hde3 /dev/hdg3 /dev/hdi3 > > /dev/hdk3" as well as "mkraid --force /dev/md2" and my > > raidtab hasn't changed except to state that HDA has failed. > > > > Is there anyway for me to force the "spare disk" to > > reconsider its purpose in life? Which is presently to make > > my data accessable so I can move to raid 10 or some other > > more simple raid format. > > > > I mean, I am sure it is some bit in the superblock that is > > miss set, but how do I fix that? > > If you are confident that you know what belongs where, then the best > thing is to recreate the array. Make sure you leave a "missing" device > so that it doesn't do a resync. > e.g. > > mdadm --create /dev/md2 -l5 -n6 /dev/hda3 /dev/hdc3 /dev/hde3 \ > missing /dev/hdi3 /dev/hdk3 > > or whatever happens to be right in your situation. > This will rewrite all superblocks but will not touch any data (unless > you try to write to md2).A > I suggest that after this you "fsck -n" the make sure the data looks > reasonably OK, and if it does, mount read-only and copy the data off. > > If fsck thinks it is trash, then maybe you got the order wrong. Just > "mdadm -S /dev/md2" and try again. Also, "mdadm --examine" will give you a good idea of how things were put together. eg. mdadm --examine /dev/hda3 -- Regards, Mike T.