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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