NAME
btrfs - control a btrfs filesystem
SYNOPSIS
btrfs subvolume snapshot <source> [<dest>/]<name>
btrfs subvolume delete <subvolume>
btrfs subvolume create [<dest>/]<name>
btrfs subvolume list <path>
btrfs subvolume set-default <id> <path>
btrfs filesystem defrag <file>|<dir> [<file>|<dir>...]
btrfs filesystem sync <path>
btrfs filesystem resize [+/-]<size>[gkm]|max <filesystem>
btrfs device scan [<device> [<device>..]]
btrfs device show <dev>|<label> [<dev>|<label>...]
btrfs device balance <path>
btrfs device add <dev> [<dev>..] <path>
btrfs device delete <dev> [<dev>..] <path> ]
btrfs help|--help|-h
DESCRIPTION
btrfs is used to control the filesystem and the files and directories
stored. It is the tool to create or destroy a snapshot or a subvolume
for the filesystem, to defrag a file or a directory, flush the data to
the disk, to resize the filesystem, to scan the device.
It is possible to abbreviate the commands unless the commands are
ambiguous. For example: it is possible to run btrfs sub snaps instead
of btrfs subvolume snapshot. But btrfs dev s is not allowed, because
dev s may be interpreted both as device show and as device scan. In
this case btrfs returns an error.
If a command is terminated by --help , the relevant help is showed. If
the passed command matches more commands, the help of all the matched
commands are showed. For example btrfs dev --help shows the help of all
device* command.
COMMANDS
subvolume snapshot <source> [<dest>/]<name>
Create a writable snapshot of the subvolume <source> with the
name <name> in the <dest> directory. If <source> is not a
subvolume, btrfs returns an error.
subvolume delete <subvolume>
Delete the subvolume <subvolume>. If <subvolume> is not a
subvolume, btrfs returns an error.
subvolume create [<dest>/]<name>
Create a subvolume in <dest> (or in the current directory if
<dest> is omitted).
subvolume list <path>
List the subvolumes present in the filesystem <path>. For every
subvolume is showed the subvolume ID (second column), the ID of
the top level subvolume (fifth column), and the path (seventh
column) relative to the top level subvolume. These <ID> may be
used by the subvolume set-default command, or at mount time via
the subvol= option.
subvolume set-default <id> <path>
Set the subvolume of the filesystem <path> which is mounted as
default. The subvolume is identified by <id>, which is returned
by the subvolume list command.
filesystem defragment <file>|<dir> [<file>|<dir>...]
Defragment files and/or directories.
device scan [<device> [<device>..]]
Scan devices for a btrfs filesystem. If no devices are passed,
btrfs scans all the block devices.
filesystem sync <path>
Force a sync for the filesystem identified by <path>.
filesystem resize [+/-]<size>[gkm]|max <path>
Resize a filesystem identified by <path>. The <size> parameter
specifies the new size of the filesystem. If the prefix + or -
is present the size is increased or decreased by the quantity
<size>. If no units are specified, the unit of the <size>
parameter defaults to bytes. Optionally, the size parameter may
be suffixed by one of the following the units designators: ’K’,
’M’, or ’G’, kilobytes, megabytes, or gigabytes, respectively.
If ’max’ is passed, the filesystem will occupy all available
space on the volume(s).
The resize command does not manipulate the size of underlying
partition. If you wish to enlarge/reduce a filesystem, you must
make sure you can expand the partition before enlarging the
filesystem and shrink the partition after reducing the size of
the filesystem.
filesystem show [<uuid>|<label>]
Show the btrfs filesystem with some additional info. If no UUID
or label is passed, btrfs show info of all the btrfs filesystem.
device balance <path>
Balance the chunks of the filesystem identified by <path> across
the devices.
device add <dev> [<dev>..] <path>
Add device(s) to the filesystem identified by <path>.
device delete <dev> [<dev>..] <path>
Remove device(s) from a filesystem identified by <path>.
EXIT STATUS
btrfs returns a zero exist status if it succeeds. Non zero is returned
in case of failure.
AVAILABILITY
btrfs is part of btrfs-progs. Btrfs filesystem is currently under heavy
development, and not suitable for any uses other than benchmarking and
review. Please refer to the btrfs wiki http://btrfs.wiki.kernel.org
for further details.
SEE ALSO
mkfs.btrfs(8)