mirror of
https://github.com/kdave/btrfs-progs
synced 2024-12-27 08:32:20 +00:00
447f976472
The message could be confusing in case there's no send in progress and the real reason is lack of permissions when deleting a subvolume. Mention the permissions as first reason. Also update documentation. Signed-off-by: David Sterba <dsterba@suse.com>
283 lines
10 KiB
ReStructuredText
283 lines
10 KiB
ReStructuredText
btrfs-subvolume(8)
|
|
==================
|
|
|
|
SYNOPSIS
|
|
--------
|
|
|
|
**btrfs subvolume** <subcommand> [<args>]
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
|
|
**btrfs subvolume** is used to create/delete/list/show btrfs subvolumes and
|
|
snapshots.
|
|
|
|
.. include:: ch-subvolume-intro.rst
|
|
|
|
SUBVOLUME AND SNAPSHOT
|
|
----------------------
|
|
|
|
A subvolume is a part of filesystem with its own independent
|
|
file/directory hierarchy. Subvolumes can share file extents. A snapshot is
|
|
also subvolume, but with a given initial content of the original subvolume.
|
|
|
|
.. note::
|
|
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 *set-default*).
|
|
|
|
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.
|
|
|
|
SUBCOMMAND
|
|
-----------
|
|
|
|
create [-i <qgroupid>] [<dest>/]<name>
|
|
Create a subvolume *name* in *dest*.
|
|
|
|
If *dest* is not given, subvolume *name* will be created in the current
|
|
directory.
|
|
|
|
``Options``
|
|
|
|
-i <qgroupid>
|
|
Add the newly created subvolume to a qgroup. This option can be given multiple
|
|
times.
|
|
|
|
delete [options] [<subvolume> [<subvolume>...]], delete -i|--subvolid <subvolid> <path>
|
|
Delete the subvolume(s) from the filesystem.
|
|
|
|
If *subvolume* is not a subvolume, btrfs returns an error but continues if
|
|
there are more arguments to process.
|
|
|
|
If *--subvolid* is used, *path* must point to a btrfs filesystem. See ``btrfs
|
|
subvolume list`` or ``btrfs inspect-internal rootid`` how to get the subvolume id.
|
|
|
|
The corresponding directory is removed instantly but the data blocks are
|
|
removed later in the background. The command returns immediately. 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.
|
|
|
|
Deleting subvolume needs sufficient permissions, by default the owner
|
|
cannot delete it unless it's enabled by a mount option
|
|
*user_subvol_rm_allowed*, or deletion is run as root.
|
|
The default subvolume (see ``btrfs subvolume set-default``) cannot be deleted and
|
|
returns error (EPERM) and this is logged to the system log. A subvolume that's
|
|
currently involved in send (see ``btrfs send``) also cannot be deleted until the
|
|
send is finished. This is also logged in the system log.
|
|
|
|
``Options``
|
|
|
|
-c|--commit-after
|
|
wait for transaction commit at the end of the operation.
|
|
|
|
-C|--commit-each
|
|
wait for transaction commit after deleting each subvolume.
|
|
|
|
-i|--subvolid <subvolid>
|
|
subvolume id to be removed instead of the <path> that should point to the
|
|
filesystem with the subvolume
|
|
-v|--verbose
|
|
(deprecated) alias for global *-v* option
|
|
|
|
find-new <subvolume> <last_gen>
|
|
List the recently modified files in a subvolume, after *last_gen* generation.
|
|
|
|
get-default <path>
|
|
Get the default subvolume of the filesystem *path*.
|
|
|
|
The output format is similar to **subvolume list** command.
|
|
|
|
list [options] [-G [\+|-]<value>] [-C [+|-]<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:
|
|
|
|
ID *ID* gen *generation* top level *parent_ID* path *path*
|
|
|
|
where *ID* is subvolume's (root)id, *generation* is an internal counter which is
|
|
updated every transaction, *parent_ID* is the same as the parent subvolume's id,
|
|
and *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.
|
|
|
|
``Options``
|
|
|
|
Path filtering:
|
|
|
|
-o
|
|
print only subvolumes below specified <path>.
|
|
-a
|
|
print all the subvolumes in the filesystem and distinguish between
|
|
absolute and relative path with respect to the given *path*.
|
|
|
|
Field selection:
|
|
|
|
-p
|
|
print the parent ID
|
|
(*parent* here means the subvolume which contains this subvolume).
|
|
-c
|
|
print the ogeneration of the subvolume, aliases: ogen or origin generation.
|
|
-g
|
|
print the generation of the subvolume (default).
|
|
-u
|
|
print the UUID of the subvolume.
|
|
-q
|
|
print the parent UUID of the subvolume
|
|
(*parent* here means subvolume of which this subvolume is a snapshot).
|
|
-R
|
|
print the UUID of the sent subvolume, where the subvolume is the result of a receive operation.
|
|
|
|
Type filtering:
|
|
|
|
-s
|
|
only snapshot subvolumes in the filesystem will be listed.
|
|
-r
|
|
only readonly subvolumes in the filesystem will be listed.
|
|
-d
|
|
list deleted subvolumes that are not yet cleaned.
|
|
|
|
Other:
|
|
|
|
-t
|
|
print the result as a table.
|
|
|
|
Sorting:
|
|
|
|
By default the subvolumes will be sorted by subvolume ID ascending.
|
|
|
|
-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* option.
|
|
--sort=rootid,gen,ogen,path
|
|
list subvolumes in order by specified items.
|
|
you can add *+* or *-* in front of each items, *+* means ascending,
|
|
*-* means descending. The default is ascending.
|
|
|
|
for *--sort* you can combine some items together by *,*, just like
|
|
*--sort=+ogen,-gen,path,rootid*.
|
|
|
|
set-default [<subvolume>|<id> <path>]
|
|
Set the default subvolume for the (mounted) filesystem.
|
|
|
|
Set the default subvolume for the (mounted) filesystem at *path*. This will hide
|
|
the top-level subvolume (i.e. the one mounted with *subvol=/* or *subvolid=5*).
|
|
Takes action on next mount.
|
|
|
|
There are two ways how to specify the subvolume, by *id* or by the *subvolume*
|
|
path.
|
|
The id can be obtained from **btrfs subvolume list**, **btrfs subvolume show** or
|
|
**btrfs inspect-internal rootid**.
|
|
|
|
show [options] <path>
|
|
Show more information about a subvolume (UUIDs, generations, times, flags,
|
|
related snapshots).
|
|
|
|
.. code-block:: none
|
|
|
|
/mnt/btrfs/subvolume
|
|
Name: subvolume
|
|
UUID: 5e076a14-4e42-254d-ac8e-55bebea982d1
|
|
Parent UUID: -
|
|
Received UUID: -
|
|
Creation time: 2018-01-01 12:34:56 +0000
|
|
Subvolume ID: 79
|
|
Generation: 2844
|
|
Gen at creation: 2844
|
|
Parent ID: 5
|
|
Top level ID: 5
|
|
Flags: -
|
|
Snapshot(s):
|
|
|
|
``Options``
|
|
|
|
-r|--rootid <ID>
|
|
show details about subvolume with root *ID*, looked up in *path*
|
|
-u|--uuid UUID
|
|
show details about subvolume with the given *UUID*, looked up in *path*
|
|
|
|
snapshot [-r] [-i <qgroupid>] <source> <dest>|[<dest>/]<name>
|
|
Create a snapshot of the subvolume *source* with the
|
|
name *name* in the *dest* directory.
|
|
|
|
If only *dest* is given, the subvolume will be named the basename of *source*.
|
|
If *source* is not a subvolume, btrfs returns an error.
|
|
|
|
``Options``
|
|
|
|
-r
|
|
Make the new snapshot read only.
|
|
-i <qgroupid>
|
|
Add the newly created subvolume to a qgroup. This option can be given multiple
|
|
times.
|
|
|
|
sync <path> [subvolid...]
|
|
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 in the meantime.
|
|
|
|
``Options``
|
|
|
|
-s <N>
|
|
sleep N seconds between checks (default: 1)
|
|
|
|
EXAMPLES
|
|
--------
|
|
|
|
Deleting a subvolume
|
|
^^^^^^^^^^^^^^^^^^^^
|
|
|
|
If we want to delete a subvolume called *foo* from a btrfs volume mounted at
|
|
*/mnt/bar* we could run the following:
|
|
|
|
.. code-block:: bash
|
|
|
|
btrfs subvolume delete /mnt/bar/foo
|
|
|
|
EXIT STATUS
|
|
-----------
|
|
|
|
**btrfs subvolume** returns a zero exit status if it succeeds. A non-zero value is
|
|
returned in case of failure.
|
|
|
|
AVAILABILITY
|
|
------------
|
|
|
|
**btrfs** is part of btrfs-progs. Please refer to the documentation at
|
|
https://btrfs.readthedocs.io or wiki http://btrfs.wiki.kernel.org for further
|
|
information.
|
|
|
|
SEE ALSO
|
|
--------
|
|
|
|
:doc:`btrfs-qgroup(8)<btrfs-qgroup>`,
|
|
:doc:`btrfs-quota(8)<btrfs-quota>`,
|
|
:doc:`btrfs-send(8)<btrfs-send>`,
|
|
:doc:`mkfs.btrfs(8)<mkfs.btrfs>`,
|
|
``mount(8)``
|