[linux-lvm] pv recovery after trashing partition table.

[Andreas Dilger]

On Oct 12, 2001  18:18 -0600, Jim N Cromie wrote:
> Miraculously, Ive successfully recovered hda[1-3], by a combination of
> luck,
> a simple partition table (1=vfat, 2=swap, 3=ext2, 4=lvm, on cylinder
> boundaries), good notes (I had the cylinder numbers mostly written down),
> and perseverance with fdisk.  I wrote experimental partition-tables
> untill I was able to mount them.
> 
> SO, WHAT IF ANY ARE MY OPTIONS ?
> 
> 1) Would a carefully considered set of 'dd' commands possibly
> restore it?   I have nothing to lose in hda4 at this point.
> 
> 2) IS IT POSSIBLE THAT DESPITE MY SUCCESS MOUNTING hda 1-3, particularly
> hda3, since thats ext2, (ie a real filesystem, with a real fsck).  Ive
> somehow got the partitions wrong, and thus pvdata is looking in the wrong
> disk sector for its meta-data  ?

Correct.  It is possible that hda3 is larger than it should be, and is
stealing the beginning of hda4.  What you really want to have is "gpart"
which _should_ find the partition tables for you automatically.

Failing that, you could look at "dumpe2fs -h /dev/hda3" to find the
previous size of the filesystem there so you know how big to make it.

Cheers, Andreas
--
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert