btrfs-subvolume - manage btrfs subvolumes
btrfs subvolume <subcommand>
is used to create/delete/list/show btrfs subvolumes and
A subvolume is a part of filesystem with its own and independent file/directory
hierarchy. Subvolumes can share file extents. A snapshot is also subvolume,
but with a given initial content of the original subvolume.
A subvolume in btrfs is not like an LVM logical volume, which is block-level
snapshot while btrfs subvolumes are file extent-based.
A subvolume looks like a normal directory, with some additional operations
described below. Subvolumes can be renamed or moved, nesting subvolumes is not
restricted but has some implications regarding snapshotting.
A subvolume in btrfs can be accessed in two ways:
• like any other directory that is
accessible to the user
• like a separately mounted filesystem
(options subvol or subvolid)
In the latter case the parent directory is not visible and accessible. This is
similar to a bind mount, and in fact the subvolume mount does exactly that.
A freshly created filesystem is also a subvolume, called top-level
internally has an id 5. This subvolume cannot be removed or replaced by
another subvolume. This is also the subvolume that will be mounted by default,
unless the default subvolume has been changed (see subcommand
A snapshot is a subvolume like any other, with given initial content. By
default, snapshots are created read-write. File modifications in a snapshot do
not affect the files in the original subvolume.
Create a subvolume <name>
is not given, subvolume <name>
created in the current directory.
Add the newly created subvolume to a qgroup. This option can be given multiple
find-new <subvolume> <last_gen>
Delete the subvolume(s) from the filesystem.
is not a subvolume, btrfs returns an error but
continues if there are more arguments to process.
The corresponding directory is removed instantly but the data blocks are removed
later in the background. The command returns immediatelly. See btrfs subvolume
sync how to wait until the subvolume gets completely removed.
The deletion does not involve full transaction commit by default due to
performance reasons. As a consequence, the subvolume may appear again after a
crash. Use one of the --commit
options to wait until the operation is
safely stored on the device.
wait for transaction commit at the end of the operation
wait for transaction commit after deleting each subvolume
List the recently modified files in a subvolume, after <last_gen>
Get the default subvolume of the filesystem <path>
The output format is similar to subvolume list
[options] [-G [+|-]<value>
] [--sort=rootid,gen,ogen,path] <path>
List the subvolumes present in the filesystem <path>
For every subvolume the following information is shown by default.
top level <ID>
path is the relative path of the subvolume to the top level subvolume. The
subvolume’s ID may be used by the subvolume set-default command, or at
mount time via the subvolid= option. If -p is given, then parent
is added to the output between ID and top level. The
parent’s ID may be used at mount time via the subvolrootid= option.
print all the subvolumes in the filesystem and distinguish between absolute and
relative path with respect to the given <path>
print the ogeneration of the subvolume, aliases: ogen or origin generation.
print the generation of the subvolume.
print only subvolumes below specified <path>
print the UUID of the subvolume.
print the parent uuid of subvolumes (and snapshots).
print the UUID of the sent subvolume, where the subvolume is the result of a
print the result as a table.
only snapshot subvolumes in the filesystem will be listed.
only readonly subvolumes in the filesystem will be listed.
-G [+|-] <value>
list subvolumes in the filesystem that its generation is >=, ⟨ or =
value. '+' means >= value, '-' means <= value, If there is neither '+'
nor '-', it means = value.
-C [+|-] <value>
list subvolumes in the filesystem that its ogeneration is >=, <= or =
value. The usage is the same to -G
list subvolumes in order by specified items. you can add '+' or '-' in front of
each items, '+' means ascending, '-' means descending. The default is
for --sort you can combine some items together by ',', just like
Set the default subvolume of the (mounted) filesystem.
There are two ways how to specify the subvolume, by <id>
or by the
path. The id can be obtained from btrfs subvolume
, btrfs subvolume show
or btrfs inspect-internal rootid
Show information of a given subvolume in the <path>
Create a writable/readonly snapshot of the subvolume <source>
the name <name>
in the <dest>
If only <dest>
is given, the subvolume will be named the basename
. If <source>
is not a subvolume, btrfs
returns an error. If -r
is given, the snapshot will be readonly.
Wait until given subvolume(s) are completely removed from the filesystem after
deletion. If no subvolume id is given, wait until all current deletion
requests are completed, but do not wait for subvolumes deleted meanwhile. The
status of subvolume ids is checked periodically.
sleep N seconds between checks (default: 1)
returns a zero exit status if it succeeds. A non-zero
value is returned in case of failure.
is part of btrfs-progs. Please refer to the btrfs wiki
for further details.
mkfs.btrfs(8), mount(8), btrfs-quota(8), btrfs-qgroup(8),