Man page - btrfs-select-super(8)
Packages contas this manual
- btrfs-rescue(8)
- btrfs-check(8)
- btrfs-find-root(8)
- btrfs(8)
- btrfs-select-super(8)
- btrfs-replace(8)
- btrfs-property(8)
- btrfsck(8)
- btrfs-receive(8)
- btrfs-map-logical(8)
- btrfs-scrub(8)
- btrfstune(8)
- btrfs(5)
- btrfs-send(8)
- btrfs-device(8)
- btrfs-restore(8)
- btrfs-subvolume(8)
- btrfs-filesystem(8)
- btrfs-quota(8)
- btrfs-qgroup(8)
- mkfs.btrfs(8)
- btrfs-ioctl(2)
- btrfs-balance(8)
- btrfs-image(8)
- btrfs-inspect-internal(8)
- fsck.btrfs(8)
- btrfs-convert(8)
apt-get install btrfs-progs
Manual
| BTRFS-SELECT-SUPER(8) | BTRFS | BTRFS-SELECT-SUPER(8) |
NAME
btrfs-select-super - overwrite primary superblock with a backup copy
SYNOPSIS
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, e.g. accidentally overwritten.
The filesystem specified by device must not be mounted.
NOTE:
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)
| April 17, 2025 | 6.14 |