From mboxrd@z Thu Jan 1 00:00:00 1970 From: Asdo Subject: Re: raid5: cannot start dirty degraded array Date: Wed, 23 Dec 2009 15:49:11 +0100 Message-ID: <4B322DE7.5010403@shiftmail.org> References: <579884013.20091223125023@kaneda.iguw.tuwien.ac.at> <52151829.20091223135001@kaneda.iguw.tuwien.ac.at> <70ed7c3e0912230525h25566bd8jae95ffab149caf65@mail.gmail.com> <953553783.20091223144402@kaneda.iguw.tuwien.ac.at> <70ed7c3e0912230548v1abacfcciadaab2888018b202@mail.gmail.com> <927342042.20091223150200@kaneda.iguw.tuwien.ac.at> <70ed7c3e0912230604m55eb6225sf68a819c6025e7b@mail.gmail.com> <1913939922.20091223153028@kaneda.iguw.tuwien.ac.at> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1913939922.20091223153028@kaneda.iguw.tuwien.ac.at> Sender: linux-raid-owner@vger.kernel.org To: Rainer Fuegenstein Cc: linux-raid List-Id: linux-raid.ids Rainer Fuegenstein wrote: > MB> mdadm -Af /dev/md0 > MB> If that doesn't work for any reason, do this: > MB> mdadm -Af /dev/md0 /dev/sdb1 /dev/sdd1 /dev/sdc1 > > MB> You can note the disk order from the output of mdadm -E > The --assemble --force needs correct order of drives to be specified!?!? I think it autodetects that (would be EXTREMELY RISKY otherwise...) Rainer, just after starting the array you can: mdadm --readonly /dev/md0 so to be sure that no writes ever happen and a resync does not happen. I suggest to take data out before doing any modifications (such as a resync), if you can. note: xfs needs -o ro,nobarrier,norecovery upon mount, in order to be mounted from a readonly array. As MB suggests, it's better to keep the the most recently failed drive out of the array if possible, in order to have more coherent data. Also true when you are going to add the first spare (that will cause a resync and regeneration of one disk).