[linux-lvm] Re: Unable to get XFS, ext3, reiserfs & LVM to coexist happily

[Andreas Dilger]

On Jan 04, 2002  10:15 +1000, Adrian Head wrote:
> Note: becareful when mounting an XFS snaphot without using "mount -t xfs" 
> otherwise i have found it will mount the snapshot as resierfs.
> See http://marc.theaimsgroup.com/?l=linux-xfs&m=100994490716530&w=2 for more 
> info on this.

This is because the reiserfs superblock is 64kB into the filesystem, and it
appears that the mkfs.xfs does not overwrite this part of the disk.  I have
heard of another person with this same problem.  It would probably behoove
the XFS folks to zero the first and last 128kB of a partition when doing
mkfs.xfs to avoid this sort of problem.

For mkfs.ext2, it will zero the first 4kB, overwrite the next tens of kB,
and also zero the last 128kB.  I should probably make sure that it will
_always_ overwrite at least the first 68kB, but with the default parameters
it will at least do so except on the smallest of filesystems (i.e. floppies).

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/