How to fix bad superblock on UFS2?
d.forsyth at ru.ac.za
Wed Jul 20 08:54:59 UTC 2011
On 20 Jul 2011 , Maxim Konovalov entreated about
"Re: How to fix bad superblock on UFS2?":
> Try to use tools/tools/find-sb to locate superblocks.
I may yet need to use that on another partition, but last night I
achieved some success by hacking fsck_ffs to display what it is
doing. By doing this I found that it considers the 'first alternate'
superblock to be the one in the LAST cylinder group.
So, by using dd to copy a working superblock to block 128 and to the
last one listed by 'newfs -N', fsck_ffs could then actually recover
some files. Since I probably broke more things on this partition
than were broken by the 'disk smoke event', I was not surprised when
only about half the drives files showed up in lost+found and the
primary folder is now empty (the whole drive is a Samba share with
quotas, so I create a folder to share so that users cannot mess with
the quota.* files). Not a problem for this partition as I have a
full level 0 dump.
I now have 2 more partitions to resurrect....
both report 'Cannot find file system superblock' though 'newfs -N'
shows a sensible list of them, so I have hope.
But, further thanks to you for pointing out find-sb, because in
googling for that I found various other very useful things, including
which at the least, points out things to avoid doing (-:
DA Fo rsyth Network Supervisor
Principal Technical Officer -- Institute for Water Research
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