I had to reboot one of my Linux systems a few days ago (November 2) because something was a little unstable, although RAID was AFAIK working just fine. This is not an online production system, so rather than try to run down the culprit, I just rebooted the box. Everything seemed to come back up just fine, so I really didn't spend too much time checking everything out. Today one of the drives in the RAID5 array was kicked out, so I removed it and added it back. It wasn't until I added the drive back that I noticed the array no longer had a write-intent bitmap. The array had an external bitmap, but it is no longer there, and I presume for some reason it was not registered when the box rebooted. I don't see anything which looks like a failure related to md in the logs. The external bitmap is in an ext2 file system in a partition of the boot drive, so the file should be available during boot prior to building the RAID array. What could be causing the bitmap to drop out? This isn't the first time it has happened. I searched /var/log for the string "md" to find the messages related to activity on the array. Is there some other string for which I should search? Here is /etc/fstab : Backup:/var/log# cat /etc/fstab # /etc/fstab: static file system information. # # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc defaults 0 0 /dev/hda2 / reiserfs defaults 0 1 /dev/hda1 /boot reiserfs notail 0 2 /dev/hda4 /etc/mdadm/bitmap ext2 defaults 0 1 /dev/hda5 none swap sw 0 0 /dev/hdb /media/cdrom0 udf,iso9660user,noauto 0 0 /dev/md0 /Backup xfs defaults 0 2 Here is /etc/mdadm/mdadm.conf Backup:/etc/mdadm# cat mdadm.conf # mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default, scan all partitions (/proc/partitions) for MD superblocks. # alternatively, specify devices to scan, using wildcards if desired. DEVICE partitions # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR lrhorer@xxxxxxxxxxx # definitions of existing MD arrays # This file was auto-generated on Thu, 14 May 2009 20:25:57 -0500 # by mkconf $Id$ PROGRAM /usr/bin/mdadm_notify DEVICE /dev/sd[a-g] ARRAY /dev/md0 level=raid5 metadata=1.2 num-devices=7 UUID=940ae4e4:04057ffc:5e92d2fb:63e3efb7 name='Backup':0 bitmap=/etc/mdadm/bitmap/md0.map -- 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
