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 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.

           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. The deletion does not involve full
           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 media.

           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

       find-new <subvolume> <last_gen>
           List the recently modified files in a subvolume, after <last_gen>
           ID.

       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> top level <ID> path <path> where 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 <ID>
           is added to the output between ID and top level. The parent’s ID
           may be used at mount time via the subvolrootid= option.

           Options

           -p
               print parent ID.

           -a
               print all the subvolumes in the filesystem and distinguish
               between absolute and relative path with respect to the given
               <path>.

           -c
               print the ogeneration of the subvolume, aliases: ogen or
               origin generation.

           -g
               print the generation of the subvolume.

           -o
               print only subvolumes below specified <path>.

           -u
               print the UUID of the subvolume.

           -q
               print the parent uuid of subvolumes (and snapshots).

           -R
               print the UUID of the sent subvolume, where the subvolume is
               the result of a receive operation

           -t
               print the result as a table.

           -s
               only snapshot subvolumes in the filesystem will be listed.

           -r
               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 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 <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.

       show <path>
           Show information of a given subvolume in the <path>.

       snapshot [-r] <source> <dest>|[<dest>/]<name>
           Create a writable/readonly 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. If -r is given, the snapshot will be readonly.

       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 meanwhile. The status of subvolume
           ids is checked periodically.

           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 2017-04-25.  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                     02/18/2017               BTRFS-SUBVOLUME(8)

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