Thank you! I gave it one more shot before attempting the script and I'm back in. I figured I'd try 0 for the beginning of the partition.
grits# disklabel sd1 # /dev/rsd1c: type: SCSI disk: SCSI disk label: Ext SSD duid: 2eeb6058175bf1f7 flags: bytes/sector: 512 sectors/track: 20 tracks/cylinder: 22 sectors/cylinder: 440 cylinders: 2131143 total sectors: 937703088 boundstart: 0 boundend: 937703088 16 partitions: # size offset fstype [fsize bsize cpg] a: 937703040 0 4.2BSD 4096 32768 1 c: 937703088 0 unused On Thu, Apr 13, 2023 at 2:51 AM <cho...@jtan.com> wrote: > Greg Thomas writes: > > I just ran through a fresh 7.3 install onto sd0 on an old 6.8 laptop and > I > > have no idea what happened to the disklabel on sd1 (during the install I > > only did an automatic disklabel on sd0). This is just a backup of my > > current laptop so not the end of the world (unless my current laptop dies > > before I have a chance to back it up again). > > Part of the solution I used previously to recover my trashed disklabel > was a script to create a partition on the disklabel with every > starting value (a simple brute force approach). This proved to be > far too slow so I resorted to hacking scan_ffs but that's because > I had other partitions and swap of unknown size to skip over first > to find the /var/backup partition that I needed. > > Since your lost partition is at the beginning of the disc somewhere > this shouldn't be much of a problem. The end sector doesn't really > matter if you'll mount the partition read-only provided it's large > enough; just don't run fsck on it. > > Something along the lines of: > > for k in `jot 2048`; do echo <blah> | disklabel -e sd0; mount -r > /dev/sd1a /mnt && echo $k; umount /mnt; done > > Where <blah> is multi-line input to disklabel to delete and create > partition a. Alternatively investigate disklabel's -R option. > > Then locate your disklabel backup, investigate -R if you didn't > already, and restore it exactly. > > Matthew > >
