On Wed, Feb 16, 2011 at 3:32 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Wed, 16 Feb 2011 10:46:32 -0500 Tobias McNulty <tobias@xxxxxxxxxxxxxxx> >> nas:~# mdadm --assemble /dev/md0 --backup-file=md0.backup /dev/sdc >> /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh >> mdadm: Failed to restore critical section for reshape, sorry. >> >> Is my data lost for good? Is there anything else I can do? > > Try above command with --verbose. > If a message about "too-old timestamp" appears, run > > export MDADM_GROW_ALLOW_OLD=1 > > and run the command again. > > In either case, post the output. Wow - it looks like that might have done the trick: nas:~# mdadm --verbose --assemble /dev/md0 --backup-file=md0.backup /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh mdadm: looking for devices for /dev/md0 mdadm: /dev/sdc is identified as a member of /dev/md0, slot 3. mdadm: /dev/sdd is identified as a member of /dev/md0, slot 2. mdadm: /dev/sde is identified as a member of /dev/md0, slot 1. mdadm: /dev/sdf is identified as a member of /dev/md0, slot 0. mdadm: /dev/sdg is identified as a member of /dev/md0, slot 5. mdadm: /dev/sdh is identified as a member of /dev/md0, slot 4. mdadm:/dev/md0 has an active reshape - checking if critical section needs to be restored mdadm: too-old timestamp on backup-metadata on md0.backup mdadm: Failed to find backup of critical section mdadm: Failed to restore critical section for reshape, sorry. nas:~# export MDADM_GROW_ALLOW_OLD=1 nas:~# mdadm --verbose --assemble /dev/md0 --backup-file=md0.backup /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh mdadm: looking for devices for /dev/md0 mdadm: /dev/sdc is identified as a member of /dev/md0, slot 3. mdadm: /dev/sdd is identified as a member of /dev/md0, slot 2. mdadm: /dev/sde is identified as a member of /dev/md0, slot 1. mdadm: /dev/sdf is identified as a member of /dev/md0, slot 0. mdadm: /dev/sdg is identified as a member of /dev/md0, slot 5. mdadm: /dev/sdh is identified as a member of /dev/md0, slot 4. mdadm:/dev/md0 has an active reshape - checking if critical section needs to be restored mdadm: accepting backup with timestamp 1297624561 for array with timestamp 1297692473 mdadm: restoring critical section mdadm: added /dev/sde to /dev/md0 as 1 mdadm: added /dev/sdd to /dev/md0 as 2 mdadm: added /dev/sdc to /dev/md0 as 3 mdadm: added /dev/sdh to /dev/md0 as 4 mdadm: added /dev/sdg to /dev/md0 as 5 mdadm: added /dev/sdf to /dev/md0 as 0 mdadm: /dev/md0 has been started with 5 drives and 1 spare. Now I see this in /etc/mdstat: md0 : active raid6 sdf[0] sdg[5](S) sdh[4] sdc[3] sdd[2] sde[1] 5860543488 blocks super 0.91 level 6, 64k chunk, algorithm 2 [5/5] [UUUUU] [=>...................] reshape = 9.9% (193691648/1953514496) finish=97156886.4min speed=0K/sec Is the 0K/sec something I need to worry about? Thanks! Tobias -- Tobias McNulty, Managing Partner Caktus Consulting Group, LLC http://www.caktusgroup.com -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html