bcachefs — manage bcachefs filesystems/devices
Contents
Commands For Debugging
These commands work on offline, unmounted filesystems.
bcachefsdump [options] device
Dump filesystem metadata
-ooutput
Required flag: Output qcow2 image(s)
-f Force; overwrite when needed
bcachefslist [options] devices...
List filesystem metadata to stdout
-b (extents | inodes | dirents | xattrs)
Btree to list from
-sinode:offset
Start position to list from
-einode:offset
End position
-iinode
List keys for a given inode number
-m (keys | formats)
-f Force fsck
-v Verbose mode List mode
Commands For Encryption
bcachefsunlockdevice
Unlock an encrypted filesystem prior to running/mounting.
bcachefsset-passphrasedevices...
Change passphrase on an existing (unmounted) filesystem.
bcachefsremove-passphrasedevices...
Remove passphrase on an existing (unmounted) filesystem.
Commands For Managing A Running Filesystem
bcachefsfsusage [options] [filesystem]
Show disk usage.
-h Print human readable sizes.
Commands For Managing Devices Within A Running Filesystem
bcachefsdeviceadd [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
bcachefsdeviceremove [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
bcachefsdeviceonlinedevice
Re-add a device to a running filesystem
bcachefsdeviceofflinedevice
Take a device offline, without removing it
-f, --force
Force, if data redundancy will be degraded
bcachefsdeviceevacuatedevice
Move data off of a given device
bcachefsdeviceset-state [options] devicenew-state-f, --force
Force, if data redundancy will be degraded
bcachefsdeviceresizedevice [size]
Resize filesystem on a device
Commands For Managing Filesystem Data
bcachefsdevicerereplicatefilesystem
Walks existing data in a filesystem, writing additional copies of any degraded data.
Commands For Migration
bcachefsmigrate [options] device
Migrate an existing filesystem to bcachefs
-ffs 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
bcachefsmigrate-superblock [options] device
Create default superblock after migrating
-ddevice
Device to create superblock for
-ooffset
Offset of existing superblock
Description
The bcachefs utility supports the following subcommands, which are documented in detail below:
Superblockcommandsformat Format one or a list of devices with bcachefs data structures.
show-super Dump superblock information to stdout.
Repaircommandsfsck Check an existing filesystem for errors.
Startup/shutdown,assemblyofmultidevicefilesystemsassemble 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.
Commandsformanagingarunningfilesystemfsusage Show disk usage
Commandsformanagingdeviceswithinarunningfilesystemdeviceadd Add a new device to an existing filesystem
deviceremove Remove a device from an existing filesystem
deviceonline Re-add an existing member to a filesystem
deviceoffline Take a device offline, without removing it
deviceevacuate Migrate data off of a specific device
deviceset-state Mark a device as failed
deviceresize Resize filesystem on a device
Commandsformanagingfilesystemdatadatarereplicate Rereplicate degraded data
Commandsforencryptionunlock 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
Commandsformigrationmigrate Migrate an existing filesystem to bcachefs, in place
migrate-superblock Add default superblock, after bcachefs migrate
Commandsfordebuggingdump Dump filesystem metadata to a qcow2 image
list List filesystem metadata in textual form
Miscellaneouscommandsversion 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)
Miscellaneous Commands
bcachefsversion
Display the version of the invoked bcachefs tool
Name
bcachefs — manage bcachefs filesystems/devices
Repair Commands
bcachefsfsck [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
bcachefsassembledevices...
Assemble an existing multi device filesystem.
bcachefsincrementaldevice
Incrementally assemble an existing multi device filesystem.
bcachefsrun
Start a partially assembled filesystem.
bcachefsstopfilesystem
Stop a running filesystem.
Superblock Commands
bcachefsformat [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.
bcachefsformat--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
bcachefsshow-super [options] device
Dump superblock information to stdout.
-f, --fields=fields
List of sections to print
-l, --layout
Print superblock layout
Synopsis
bcachefscommand [options] [arguments]
