UFS file system problem in either stable or current

[Dan Strick]

On Wed, 22 Oct 2003 06:23:20 -0500, Peter Schultz wrote:
>
> Dan Strick wrote:
> > There seems to be an inconsistency between release 4.9-RC and 5.1 ufs
> > support.  If I fsck the same ufs (type 1 of course) file system on
> > both releases, each claims that the other has left incorrect
> > summary data in the superblock.  Presumably only one can be correct.
> > I just don't know which to blame.
> > ...
>
> There is no problem AFAIK, you just have to fsck with the matching 
> executable.  A lot has changed with FreeBSD 5, spend some time with the 
> -current archive and you will learn more.  I'm sure you noticed how your 
> findings are consistently inconsistent.

Thanks for the pointer.  I eventually found at least part of the
discussion in the -current archive.  I interpret the discussion as
follows:

The 5.x UFS1 file system turns out to be slightly incompatible with
earlier UFS file systems.  The problem is only that it keeps the
summary data in a different location in the superblock, but that is
sufficient to make the file systems incompatible.  There seems to be
no interest in making them compatible.

Suggestion: if FreeBSD 5 used a different clean flag and FreeBSD 4/5
always cleared the other's clean flag whenever they rewrote a superblock,
the file systems would automatically be refscked whenever you switched
between operating systems but not after a normal reboot.

Dan Strick
strick at covad.net