hi, i've been happily running RAID1 for years on my system.
i have two IDE hard disks each with 4 partitions:
Device Boot Start End Blocks Id System
/dev/sda1 * 1 16 128488+ fd Linux RAID autodetect
/dev/sda2 17 3663 29294527+ fd Linux RAID autodetect
/dev/sda3 3664 14471 86815260 fd Linux RAID autodetect
/dev/sda4 14472 14593 979965 82 Linux swap / Solaris
/dev/sdb is an identical disk and partitioned exactly the same.
root@ubuntu:~/Desktop# mount | grep md
/dev/md0 on /boot type ext3 (rw,relatime)
/dev/md1 on / type ext3 (rw,relatime,errors=remount-ro)
a bad past experience with RAIDed swap meant i don't RAID it anymore:
root@ubuntu:~/Desktop# swapon -s
Filename Type Size Used Priority
/dev/sda4 partition 979956 0 -1
/dev/sdb4 partition 979956 0 -2
ok so far. so where's /dev/md2? well that's where i normally mount all my user data and /home and md2 is /dev/sd[ab]3. now the fun starts.
i'm running ubuntu 8.10 and noticed that trackerd was stuck indexing the last directory (approximately 5678/5678). i restarted indexing and it got stuck again. hmmm - now i'm interested. my email client is evolution and that was starting to complain about the database and i lost an email or two. now i'm worried.
a reboot won't harm, i thought. wrong:
fsck 1.41.3 (12-Oct-2008)
e2fsck 1.41.3 (12-Oct-2008)
fsck.ext3: Group descriptors look bad... trying backup blocks...
fsck.ext3: Bad magic number in super-block while trying to open /dev/sda3
The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
i stopped /dev/md2, booted and logged in as root (doesn't use /home at all) and have tried to fsck /dev/sda3 and /dev/sdb3
same fsck error as above on both. and the -b 8193 option has no effect.
i tried mdadm --zero-superblock /dev/sda3
and rebuilt the array, but all that came back after a disk sync was the corrupted file system error.
my understanding isn't great, but i think the RAID is fine, and it's the file system that's broken. if i could fix /dev/sda3 i'll happily zero sdb3 (dd -if=/dev/zero -of=/dev/sdb3
) and then re-assemble the RAID, but i just can't seem to fix sda3.
any suggestions, and am i even going about this the right way?
thanks in advance