topic Re: superblocks backup in Operating System - Linux

superblocks backup

Amit_68 — Fri, 25 Mar 2005 08:38:14 GMT

where we can see backup of superblocks in Linux.Like we can see /var/adm/sbtab in HP-UX.
and while trying to run fsck it shows exception....bad superblock magic number in /dev/hda try fsck -b 1843.

Re: superblocks backup

Florian Heigl (new acc) — Fri, 25 Mar 2005 17:03:15 GMT

The superblock copies are spread over the filesystem.
to find them You will usually need information on the block size of the filesystem.

what happens if You try fsck -b 1843?

in the worst case You can use a loop to seek over the whole filesystem like (example!)

divide filesystem size through blocks
pos=0;while [ $fssize -ge $pos ];
do
fsck -n -b $pos /dev/vgdata/lvol01
done

Re: superblocks backup

Chakravarthi — Mon, 28 Mar 2005 05:14:25 GMT

hi amit,

check the attached link

http://www.edseek.com/archives/2004/02/25/ext3-filesystem-bad-superblock-recovery/