NAME

     bcachefs — manage bcachefs filesystems/devices

SYNOPSIS

     bcachefs command [options] [arguments]

DESCRIPTION

     The bcachefs utility supports the following subcommands, which are documented in detail
     below:

   Superblock commands
     format              Format one or a list of devices with bcachefs data structures.
     show-super          Dump superblock information to stdout.

   Repair commands
     fsck                Check an existing filesystem for errors.

   Startup/shutdown, assembly of multi device filesystems
     assemble            Assemble an existing multi device filesystem
     incremental         Incrementally assemble an existing multi device filesystem
     run                 Start a partially assembled filesystem.
     stop                Stop a running filesystem.

   Commands for managing a running filesystem
     fs usage            Show disk usage

   Commands for managing devices within a running filesystem
     device add          Add a new device to an existing filesystem
     device remove       Remove a device from an existing filesystem
     device online       Re-add an existing member to a filesystem
     device offline      Take a device offline, without removing it
     device evacuate     Migrate data off of a specific device
     device set-state    Mark a device as failed
     device resize       Resize filesystem on a device

   Commands for managing filesystem data
     data rereplicate    Rereplicate degraded data

   Commands for encryption
     unlock              Unlock an encrypted filesystem prior to running/mounting
     set-passphrase      Change passphrase on an existing (unmounted) filesystem
     remove-passphrase   Remove passphrase on an existing (unmounted) filesystem

   Commands for migration
     migrate             Migrate an existing filesystem to bcachefs, in place
     migrate-superblock  Add default superblock, after bcachefs migrate

   Commands for debugging
     dump                Dump filesystem metadata to a qcow2 image
     list                List filesystem metadata in textual form

   Miscellaneous commands
     version             Display the version of the invoked bcachefs tool

Superblock commands

     bcachefs format [options] devices ...
             Format one or a list of devices with bcachefs data structures.  You need to do this
             before you create a volume.

             Device specific options must come before corresponding devices, e.g.
                   bcachefs format --group=ssd /dev/sda --label=hdd /dev/sdb

             -b, --block=size
                     block size, in bytes (e.g. 4k)

             --btree_node=size
                     Btree node size, default 256k

             --metadata_checksum_type=(none | crc32c | crc64)
                     Set metadata checksum type (default: crc32c).

             --data_checksum_type=(none | crc32c | crc64)
                     Set data checksum type (default: crc32c).

             --compression=(none | lz4 | gzip | zstd)
                     Set compression type (default: none).

             --data_replicas=number
                     Number of data replicas

             --metadata_replicas=number
                     Number of metadata replicas

             --replicas=number
                     Sets both data and metadata replicas

             --encrypted
                     Enable whole filesystem encryption (chacha20/poly1305); passphrase will be
                     prompted for.

             --no_passphrase
                     Don't encrypt master encryption key

             --error_action=(continue | remount-ro | panic)
                     Action to take on filesystem error (default: remount-ro)

             -L, --label=label
                     Create the filesystem with the specified label

             -U, --uuid=uuid
                     Create the filesystem with the specified uuid

             -f, --force
                     Force the filesystem to be created, even if the device already contains a
                     filesystem.

             Device specific options:

             --fs_size=size
                     Create the filesystem using size bytes on the subsequent device.

             --bucket=size
                     Specifies the bucket size; must be greater than the btree node size

             --discard
                     Enable discards on subsequent devices

             -q, --quiet
                     Only print errors

     bcachefs show-super [options] device
             Dump superblock information to stdout.

             -f, --fields=fields
                     List of sections to print

             -l, --layout
                     Print superblock layout

Repair commands

     bcachefs fsck [options] devices ...
             Check an existing filesystem for errors.

             -p      Automatic repair (no questions)

             -n      Don't repair, only check for errors

             -y      Assume "yes" to all questions

             -f      Force checking even if filesystem is marked clean

             -v      Be verbose

Startup/shutdown, assembly of multi device filesystems

     bcachefs assemble devices ...
             Assemble an existing multi device filesystem.

     bcachefs incremental device
             Incrementally assemble an existing multi device filesystem.

     bcachefs run
             Start a partially assembled filesystem.

     bcachefs stop filesystem
             Stop a running filesystem.

Commands for managing a running filesystem

     bcachefs fs usage [options] [filesystem]
             Show disk usage.

             -h      Print human readable sizes.

Commands for managing devices within a running filesystem

     bcachefs device add [options] device
             Add a device to an existing filesystem.

             --fs_size=size
                     Size of filesystem on device

             --bucket=size
                     Set bucket size

             --discard
                     Enable discards

             -f, --force
                     Use device even if it appears to already be formatted

     bcachefs device remove [options] device
             Remove a device from a filesystem

             -f, --force
                     Force removal, even if some data couldn't be migrated

             --force-metadata
                     Force removal, even if some metadata couldn't be migrated

     bcachefs device online device
             Re-add a device to a running filesystem

     bcachefs device offline device
             Take a device offline, without removing it

             -f, --force
                     Force, if data redundancy will be degraded

     bcachefs device evacuate device
             Move data off of a given device

     bcachefs device set-state [options] device new-state

             -f, --force
                     Force, if data redundancy will be degraded

     bcachefs device resize device [size]
             Resize filesystem on a device

Commands for managing filesystem data

     bcachefs device rereplicate filesystem
             Walks existing data in a filesystem, writing additional copies of any degraded data.

Commands for encryption

     bcachefs unlock device
             Unlock an encrypted filesystem prior to running/mounting.

     bcachefs set-passphrase devices ...
             Change passphrase on an existing (unmounted) filesystem.

     bcachefs remove-passphrase devices ...
             Remove passphrase on an existing (unmounted) filesystem.

Commands for migration

     bcachefs migrate [options] device
             Migrate an existing filesystem to bcachefs

             -f fs   Root of filesystem to migrate

             --encrypted
                     Enable whole filesystem encryption (chacha20/poly1305)

             --no_passphrase
                     Don't encrypt master encryption key

             -F      Force, even if metadata file already exists

     bcachefs migrate-superblock [options] device
             Create default superblock after migrating

             -d device
                     Device to create superblock for

             -o offset
                     Offset of existing superblock

Commands for debugging

     These commands work on offline, unmounted filesystems.

     bcachefs dump [options] device
             Dump filesystem metadata

             -o output
                     Required flag: Output qcow2 image(s)

             -f      Force; overwrite when needed

     bcachefs list [options] devices ...
             List filesystem metadata to stdout

             -b (extents | inodes | dirents | xattrs)
                     Btree to list from

             -s inode:offset
                     Start position to list from

             -e inode:offset
                     End position

             -i inode
                     List keys for a given inode number

             -m (keys | formats)

             -f      Force fsck

             -v      Verbose mode List mode

Miscellaneous commands

     bcachefs version
             Display the version of the invoked bcachefs tool

EXIT STATUS

     The bcachefs utility exits 0 on success, and >0 if an error occurs.