rtc@westford.ccur.com (Robert Chesler) (05/07/91)
I trashed the root partition on an ULTRIX system disk. It had a non-standard partition table since it was a non-DEC disk. There are two partitions out on the disk that I'd sure like to find. Anyone have any tricks or tools to help do this? --Robert ========================================================================== Robert Chesler rtc@westford.ccur.com decvax!chesler!rob
mouse@thunder.mcrcim.mcgill.edu (der Mouse) (05/13/91)
In article <62039@masscomp.westford.ccur.com>, rtc@westford.ccur.com (Robert Chesler) writes: > I trashed the root partition on an ULTRIX system disk. It had a > non-standard partition table since it was a non-DEC disk. There are > two partitions out on the disk that I'd sure like to find. Anyone > have any tricks or tools to help do this? Read the disk sector by sector, looking for a block containing FS_MAGIC in the appropriate spot. You may get some false positives, but you should find the partition's superblock. To weed out the false positives, do some of the simple checks fsck does, like make sure fs_size, fs_dsize, fs_ncg, fs_bsize, fs_fsize, fs_frag, etc, etc are sane (eg, positive, less than something reasonable...). That should get the number of false positives down to where you can start using fsck to test for them, but if you really want to finish the job automatically, look for many identical superblocks in sectors whose numbers are in arithmetical progression - they'll be the backup superblocks. (Assuming your Ultrix uses the Berkeley FFS, of course.) der Mouse old: mcgill-vision!mouse new: mouse@larry.mcrcim.mcgill.edu