From: sct@dcs.ed.ac.uk (Stephen Tweedie) Subject: Re: Request to FS developers... superblock corruption Date: 2 Apr 1993 00:47:48 GMT
> In <1993Apr1.172043.4168@kf8nh.wariat.org> bsa@kf8nh.wariat.org (Brandon S. Allbery) writes:
>>Some superblock problems can be fixed easily; others are pretty much
>>final. Although someone might want to look into using something
>>like BSD's backup superblocks --- but since none of the Linux fs's
>>have cylinder groups, I'm not sure where you'd put them or how they
>>would be found if the primary superblock gets hosed.
> Er, ext2fs has cylinder groups, and it keeps backup superblocks.
> e2fsck doesn't currently use them, but I suspect that's only a
> matter of time.
Yes, almost right. In fact, ext2fs does not go the full hog and
create a separate block group for every single cylinder, but does use
8MB block groups with a copy of the superblock in each group. The
kernel keeps all of the copies uptodate, and a future version of the
efsck program will be able to restore corrupted superblocks.
Cheers,
Stephen Tweedie.