On Tue, 2008-03-25 at 16:54 -0500, Bob Peterson wrote: > On Tue, 2008-03-25 at 18:47 +0000, DRand@xxxxxxxxxxx wrote: > > > > Help! > > > > We have accidentally formatted a GFS cluster with this command. > > > > mkfs.gfs -J 1024 -j 4 -p lock_gulm -t aicluster:cmsgfs /dev/sda > > > > We were using the disk as a backup system. We need to unformat it.. > > Are there any tools that will let us get at the disk directory? > > > > Damon. > > Hi Damon, > > The short answer is no. > There are no tools I'm aware of to "unformat" a gfs file system. > However: > > Your ability to get back data depends on how the file system > looked before the mkfs. If /dev/sda was ext3 before, I don't know > what you can do to recover it. I do know that gfs and ext3 have > their superblocks in different places, and I don't know ext3. I don't know GFS, but block 0 of the partition is here the primary superblock is on ext3. Fortunately, ext3 stores a pile of backup superblocks throughout the disk - but I forgot the algorithm to determine what block #s contained them. > The same pretty much goes for every other file system (xfs, vfat, etc.). e2fsck -b [alternate_superblock_address] *might* help if you can figure out an alternate superblock location. Some of your data will be unrecoverable, and some will be unrecognizable (e.g. stored as a numbered file in /lost+found of the partition after e2fsck completes). -- Lon -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
