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 --group=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_type=(none | lz4 | gzip)
                       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.

Debian                                            May 26, 2018                                       BCACHEFS(8)