fs oddity when moving from 4.4 to 5.3
Jan Pechanec
jp at devnull.cz
Thu Feb 3 15:47:49 PST 2005
hi, after RW mounting UFS1 filesystem created using sysinstall under
4.4 to 5.3 and extracting 1/2 of the only file there (tarball), the file got
lost. Now I got that disk to salvage as much as I can. I don't want to give
much details since I think it would be too much, but is there any chance
that some changes in the code could do that? Fsck doesn't complain, the
directory chunk for the file is now part of larger free chunk etc., but the
file was not manually deleted, bash history was checked.
just one thing: 'dumpfs -m' on 5.3 and then 'newfs -N...' shows:
/dev/ad1s1e: 38158.3MB (78148160 sectors) block size 8192, fragment size 1024
using 846 cylinder groups of 45.15MB, 5779 blks, 11584 inodes.
super-block backups (for fsck -b #) at:
32, 92496, 184960, 277424, 369888, 462352, 554816, 647280, 739744, 832208,
the same 'newfs -N' (without '-O 1') on 4.11 shows this:
/dev/ad1s1e: 78148160 sectors in 19080 cylinders of 1 tracks, 4096 sectors
38158.3MB in 868 cyl groups (22 c/g, 44.00MB/g, 10944 i/g)
super-block backups (for fsck -b #) at:
32, 90144, 180256, 270368, 360480, 450592, 540704, 630816, 720928, 811040,
you can see that number of cylinder groups is different (and
superblocks too of course) and no wonder that all superblocks except of 32
don't work with 'fsck -b'. The real 2nd backup superblock (manually found
using the magic) is 65568, which is quite far from what 5.3/4.11 thinks.
Apparently the real number of cylinder group is very different. Can anyone
explain that, please? I'm quite confused. Tomorrow I will install 4.4 to see
the filesystem behaviour there.
root at compaq.hide:~# fsck -b 65568 -n /dev/ad1s1e
Alternate super block location: 65568
** /dev/ad1s1e (NO WRITE)
** Last Mounted on
** Phase 1 - Check Blocks and Sizes
thank you, Jan.
--
Jan Pechanec <jp (at) devnull (dot) cz>
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