Re: Lost file allocation table on USB hard drive
Stephen Gregory <[email protected]>
| Newsgroups | gmane.user-groups.linux.ottawa.general |
|---|---|
| Message-ID | <[email protected]> |
james terris wrote: > > Do you have some more information about what steps you did? I generally use fdisk in this type of case because it doesn't do anything automagically. Fdisk only works on the partition table and won't touch the filesystems. If the table is missing or very corrupt fdisk will ask to create a new table which I do. Press p to display the current partition table. If the table is only partially corrupt there will be nonsense entries. Delete the entries with d. Recreate the partition table entries with n. If you had a single partition then it should be easy. Just create a single partition. It is more important to get the start of the partition correct then the end. (with ext2,3,4 filesystems at least). Exit fdisk with w. Pay attention to the exit messages. You may need to reboot to re-read the partition table. Try to mount the recreated partition read-only. If it was just the partition table that was corrupt you should be fine. If you did not get the partition correct you can keep trying as long as you don't write to the filesystems. Run fsck to check. If you do run into errors do not blindly accept the changes as the primary superblock may be corrupt. Try using one of the alternate superblocks. See man fsck.ext3. On my ext3 filesystems there are backup super blocks here: Primary superblock at 0, Group descriptors at 1-24 Backup superblock at 32768, Group descriptors at 32769-32792 Backup superblock at 98304, Group descriptors at 98305-98328 Backup superblock at 163840, Group descriptors at 163841-163864 Backup superblock at 229376, Group descriptors at 229377-229400 Backup superblock at 294912, Group descriptors at 294913-294936 Backup superblock at 819200, Group descriptors at 819201-819224 Backup superblock at 884736, Group descriptors at 884737-884760 Backup superblock at 1605632, Group descriptors at 1605633-1605656 Backup superblock at 2654208, Group descriptors at 2654209-2654232 Backup superblock at 4096000, Group descriptors at 4096001-4096024 Backup superblock at 7962624, Group descriptors at 7962625-7962648 Backup superblock at 11239424, Group descriptors at 11239425-11239448 Backup superblock at 20480000, Group descriptors at 20480001-20480024 Backup superblock at 23887872, Group descriptors at 23887873-23887896 Backup superblock at 71663616, Group descriptors at 71663617-71663640 Backup superblock at 78675968, Group descriptors at 78675969-78675992 On one of my small ext2 filesystems there are backup super blocks here: Primary superblock at 1, Group descriptors at 2-2 Backup superblock at 8193, Group descriptors at 8194-8194 Backup superblock at 24577, Group descriptors at 24578-24578 Backup superblock at 40961, Group descriptors at 40962-40962 Backup superblock at 57345, Group descriptors at 57346-57346 Backup superblock at 73729, Group descriptors at 73730-73730 Backup superblock at 204801, Group descriptors at 204802-204802 Backup superblock at 221185, Group descriptors at 221186-221186 good luck. -- OCLUG general discussion list [email protected] http://oclug.on.ca/mailman/listinfo/oclug