Name
btrfs-select-super - overwrite primary superblock with a backup copySynopsis
btrfs-select-super -s number <device>Description
Destructively overwrite all copies of the superblock with a specified copy. This helps in certain cases, for example when write barriers were disabled during a power failure and not all superblocks were written, or if the primary superblock is damaged, eg. accidentally overwritten. The filesystem specified by device must not be mounted. NOTE: Prior to overwriting the primary superblock, please make sure that the backup copies are valid! To dump a superblock use the btrfs inspect-internal dump-super command. Then run the check (in the non-repair mode) using the command btrfs check -s where -s specifies the superblock copy to use. Superblock copies exist in the following offsets on the device:primary: 64KiB (65536)
1st copy: 64MiB (67108864)
2nd copy: 256GiB (274877906944) A superblock size is 4KiB (4096).
Options
-s|--super <N> use Nth superblock copy, valid values are 0 1 or 2 if the respective superblock offset is within the device size
See Also
- btrfs(8)