The btrfs rescue command is a command-line utility in Linux that is used to perform various rescue and recovery operations on a btrfs file system. btrfs rescue is a utility that is included in the btrfs-progs package, which is a collection of tools and libraries for managing btrfs file systems.
Btrfs is a copy-on-write (CoW) file system that is included in the Linux kernel and is known for its advanced features and capabilities, such as snapshotting, incremental backups, and more. btrfs rescue is a tool that allows you to perform various recovery and rescue operations on a btrfs file system in case of data loss or corruption.
For more information on using btrfs rescue, you can consult the btrfs-progs documentation or use the btrfs rescue –help command to view a list of available options and usage examples.
btrfs rescue Command Examples
1. Rebuild the filesystem metadata tree (very slow):
# btrfs rescue chunk-recover /path/to/partition
2. Fix device size alignment related problems (e.g. unable to mount the filesystem with super total bytes mismatch):
# btrfs rescue fix-device-size /path/to/partition
3. Recover a corrupted superblock from correct copies (recover the root of filesystem tree):
# btrfs rescue super-recover /path/to/partition
4. Recover from an interrupted transactions (fixes log replay problems):
# btrfs rescue zero-log /path/to/partition
5. Create a /dev/btrfs-control control device when mknod is not installed:
# btrfs rescue create-control-device