On Tuesday November 7, lists@xxxxxxxxx wrote: > I recently installed a server with mirrored disks using software RAID. > Everything was working fine for a few days until a normal reboot (not > the first). Now the machine will not boot because it appears the > superblock is wrong on some of the RAID devices on the first disk. > > The rough layout of the disks (sda and sdb): > > sdx1 (md0) - / > sdx2 (md1) - /var > sdx3 (md2) - /usr > extended partition with swap > sdx6 (md3) - /opt > > The exact error is: > > "invalid superblock checksum on sda3 > sda3 has invalid sb, not importing!" > > Booting into a live CD, mdadm -E /dev/sdaX shows that the checksum is > not what would be expected for sda1,2,3 but is fine for sda6. All of > the checksums on drive sdb are correct. I'm surprised it doesn't boot then. How are the arrays being assembled? A more complete kernel log would help. > > The state is "clean" for all partitions, working 2, active 2 and > failed 0. The table for sdb1,2,3 shows that the first device has been > removed and is no longer an active mirror. > > What is the best way to proceed here? Can I somehow sync from the > second disk, which appears to have the correct checksums? Is there an > easy way to fix this that wont involve loosing the data? While booted from the live CD you should be able to mdadm -AR /dev/md0 /dev/sdb1 mdadm /dev/md0 --add /dev/sda1 and repeat for 2 and 3. That will cause a recovery of all arrays but you won't lose any data. It is very odd that the checksums are all wrong though. Kernel version? mdadm version? hardware architecture? NeilBrown - 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
