Provided by: bcachefs-tools_24+really1.3.4-2build2_amd64 
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.
Mount commands
mount Mount a filesystem.
Repair commands
fsck Check an existing filesystem for errors.
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 --label=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
Mount commands
bcachefs mount [options] device mountpoint
Mount a filesystem. The device can be a device, a colon-separated list of devices, or
UUID=<UUID>. The mountpoint is the path where the filesystem should be mounted. If not set, then
the filesystem won't actually be mounted but all steps preceeding mounting the filesystem (e.g.
asking for passphrase) will still be performed.
-o options
Mount options provided as a comma-separated list. See userguide for complete list.
degraded
Allow mounting with data degraded
verbose
Extra debugging info during mount/recovery
fsck Run fsck during mount
fix_errors
Fix errors without asking during fsck
read_only
Mount in read only mode
version_upgrade
-k, --key-location=(fail | wait | ask)
Where the password would be loaded from. (default: ask).
fail don't ask for password, fail if filesystem is encrypted.
wait wait for password to become available before mounting.
ask prompt the user for password.
-v Be verbose. Can be specified more than once.
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
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] new-state device
new-state=(rw | ro | failed | spare)
-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 March 7, 2023 BCACHEFS(8)