NAME | SYNOPSIS | DESCRIPTION | SUBVOLUME AND SNAPSHOT | SUBCOMMAND | EXIT STATUS | AVAILABILITY | SEE ALSO | COLOPHON

BTRFS-SUBVOLUME(8)              Btrfs Manual              BTRFS-SUBVOLUME(8)

NAME         top

       btrfs-subvolume - manage btrfs subvolumes

SYNOPSIS         top

       btrfs subvolume <subcommand> [<args>]

DESCRIPTION         top

       btrfs subvolume is used to create/delete/list/show btrfs subvolumes
       and snapshots.

SUBVOLUME AND SNAPSHOT         top

       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         top

       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 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.

           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.

           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.

           -v|--verbose
               verbose output of operations.

       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 <ID> path <path>

           where ID is subvolume’s id, gen is an internal counter which is
           updated every transaction, top level is the same as 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

               -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 subvolume <path> regarding UUIDs,
           times, generations, flags and related snapshots.

               /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
               rootid of the subvolume.

           -u|--uuid
               UUID of the subvolume.

       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)

EXIT STATUS         top

       btrfs subvolume returns a zero exit status if it succeeds. A non-zero
       value is returned in case of failure.

AVAILABILITY         top

       btrfs is part of btrfs-progs. Please refer to the btrfs wiki
       http://btrfs.wiki.kernel.org for further details.

SEE ALSO         top

       mkfs.btrfs(8), mount(8), btrfs-quota(8), btrfs-qgroup(8),

COLOPHON         top

       This page is part of the btrfs-progs (btrfs filesystem tools)
       project.  Information about the project can be found at 
       ⟨https://btrfs.wiki.kernel.org/index.php/Btrfs_source_repositories⟩.
       If you have a bug report for this manual page, see
       ⟨https://btrfs.wiki.kernel.org/index.php/Problem_FAQ#How_do_I_report_bugs_and_issues.3F⟩.
       This page was obtained from the project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git⟩
       on 2019-05-09.  (At that time, the date of the most recent commit
       that was found in the repository was 2019-02-25.)  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

Btrfs v4.6.1                     03/06/2019               BTRFS-SUBVOLUME(8)

Pages that refer to this page: tmpfiles.d(5)btrfs(8)btrfs-qgroup(8)btrfs-quota(8)