BTRFS-SELECT-SUPER - reference manual online

Overwrite superblock with a backup.

BTRFS-SELECT-SUPER(8)                      Btrfs Manual                     BTRFS-SELECT-SUPER(8)

NAME btrfs-select-super - overwrite superblock with a backup
SYNOPSIS btrfs-select-super -s number dev
DESCRIPTION btrfs-select-super destructively overwrites all copies of the superblock with a specified copy. This helps with certain cases of damage, especially when barriers were disabled during a power failure. You can find a valid copy of the superblock with btrfs check -s. The filesystem specified by dev must not be mounted.
OPTIONS -s|--super <superblock> use <superblock>th superblock copy, valid values are 0 up to 2 if the respective superblock offset is within the filesystem
SEE ALSO btrfsck check(8)
Btrfs v4.4 06/15/2017 BTRFS-SELECT-SUPER(8)