PART 3: Update: I'm even more concerned about this now, because I just started the newest reshaping to add a new drive with: mdadm --grow -c 256 --raid-devices=5 --backup-file=/grow_md0.bak /dev/md0 And the system output: mdadm: Need to backup 768K of critical section.. cat /proc/mdstat shows the reshaping is proceeding, Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] md0 : active raid6 sdi1[0] sdf1[5] md1p1[4] sdj1[3] sdh1[1] 2929691136 blocks super 1.2 level 6, 128k chunk, algorithm 2 [5/5] [UUUUU] [>....................] reshape = 0.0% (56576/1464845568) finish=2156.9min speed=11315K/sec md1 : active raid0 sdg1[0] sdk1[1] 1465141760 blocks super 1.2 128k chunks unused devices: <none> but I've checked for /grow_md0.bak and it's not there. So it looks like for some reason it ignored my backup file option. This scares me, because if I experience the lockup again and am forced to reboot, without a backup file I'm afraid my array will be hosed. I'm also afraid to stop it cleanly right now for the same reason. So in addition to fixing the lockup itself, does anyone know if there's a way to either cancel this reshaping or belatedly add the backup file in a different way so it will be recoverable? It's only at 1% and says it will take another 2193 minutes. Mike -- 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