From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Help - power failure during RAID6 grow Date: Sat, 27 Aug 2011 06:51:51 +1000 Message-ID: <20110827065151.03b2d930@notabene.brown> References: <20110826151803.GA7595@majestic.pimp.org.za> <20110826161746.GB7595@majestic.pimp.org.za> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110826161746.GB7595@majestic.pimp.org.za> Sender: linux-raid-owner@vger.kernel.org To: Michael-John Turner Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, 26 Aug 2011 17:17:46 +0100 Michael-John Turner wrote: > On Fri, Aug 26, 2011 at 04:18:03PM +0100, Michael-John Turner wrote: > [...] > > I tried stopping and re-assembling by hand, but get the following: > > # mdadm --assemble /dev/md20 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1 /dev/sdh1 > > mdadm: /dev/md20 assembled from 5 drives and 1 spare - not enough to start the array. > [...] > > A bit more info. If I try an assemble with -vv, I get the following: > mdadm: /dev/sdh1 is identified as a member of /dev/md20, slot 4. > mdadm: /dev/sdf1 is identified as a member of /dev/md20, slot 2. > mdadm: /dev/sdg1 is identified as a member of /dev/md20, slot 3. > mdadm: /dev/sde1 is identified as a member of /dev/md20, slot 1. > mdadm: /dev/sdd1 is identified as a member of /dev/md20, slot 0. > mdadm: /dev/sdb1 is identified as a member of /dev/md20, slot 6. > mdadm: /dev/sdc1 is identified as a member of /dev/md20, slot 5. > mdadm: /dev/sda1 is identified as a member of /dev/md20, slot -1. > mdadm:/dev/md20 has an active reshape - checking if critical section needs to be restored > mdadm: too-old timestamp on backup-metadata on device-5 > mdadm: too-old timestamp on backup-metadata on device-6 > mdadm: too-old timestamp on backup-metadata on device-8 > mdadm: added /dev/sde1 to /dev/md20 as 1 > mdadm: added /dev/sdf1 to /dev/md20 as 2 > mdadm: added /dev/sdg1 to /dev/md20 as 3 > mdadm: added /dev/sdh1 to /dev/md20 as 4 > mdadm: added /dev/sdc1 to /dev/md20 as 5 > mdadm: added /dev/sdb1 to /dev/md20 as 6 > mdadm: no uptodate device for slot 7 of /dev/md20 > mdadm: added /dev/sda1 to /dev/md20 as -1 > mdadm: added /dev/sdd1 to /dev/md20 as 0 > mdadm: /dev/md20 assembled from 5 drives and 1 spare - not enough to start the array. > > Taking the contents of my previous mail into account (with the details > of each array member), is it safe to do an assemble with > MDADM_GROW_ALLOW_OLD=1? > > -mj Leave sda1 out of the list - it looks too much like a spare. Sometime must have reset the metadata on it. You can live without it so do so for now. Assemble the array with the rest of the devices and give the "--force" flag so it will update the event counts to all be in sync. And do this with MDADM_GROW_ALLOW_OLD=1 set. This should finish the reshape and give you a singly degraded 8 device RAID6. Then add sda1 back in and it will recover and the array will be optimal. NeilBrown