First, I'll start with an apology - I have little (~nothing) in the way of hard data to back up this question, but it is now just a matter of personal interest as the problem appears to be fixed. Background: Last week I tried to upgrade a kernel (ubuntu distro 16.04) but that failed due to out of space (the system was originally built when kernels were much smaller and I have now got to the point where it is not possible to have two kernels on the /boot partitian). On reboot the boot failed with a great deal of disk noise which persisted. Booting into recovery worked, and the noise was now knowable to be coming from a RAID resync of /dev/md0 (RAID10) after I dropped into a root shell. I allowed this to complete and then went back to resume the normal boot. This failed as before. Repeating the process above, I found that the RAID was again unsynced an doing a resync. This has now resolved - I again allowed the resync to complete and then did a /sbin/reboot from the CLI rather than going back to the recovery menu and continuing the boot from the menu. Question: What is a/are likely cause(s) for a resync to not persist over a reboot? Thanks and apologies for the dearth of information (if more will be helpful I can add in a follow-up, but since the RAID is now working I am not sure what will be helpful). Dan Current detail (now all working): $ sudo mdadm --detail /dev/md0 /dev/md0: Version : 0.90 Creation Time : Tue Sep 29 17:41:02 2009 Raid Level : raid10 Array Size : 974558208 (929.41 GiB 997.95 GB) Used Dev Size : 974558208 (929.41 GiB 997.95 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Mon Oct 24 09:47:52 2016 State : active Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : far=4 Chunk Size : 256K UUID : xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx Events : 0.48263 Number Major Minor RaidDevice State 0 8 18 0 active sync /dev/sdb2 1 8 2 1 active sync /dev/sda2 2 8 34 2 active sync /dev/sdc2 3 8 50 3 active sync /dev/sdd2 $ cat /proc/mdstat Personalities : [raid10] [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] md1 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0] 152512 blocks [4/4] [UUUU] md0 : active raid10 sdd2[3] sdc2[2] sda2[1] sdb2[0] 974558208 blocks 256K chunks 4 far-copies [4/4] [UUUU] unused devices: <none> -- 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
