btrfs-subvolume(8) — Linux manual page


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.


       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.


           A subvolume in btrfs is not like an LVM logical volume, which
           is block-level snapshot while btrfs subvolumes are file

       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

       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.


           -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.

           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


               wait for transaction commit at the end of the operation.

               wait for transaction commit after deleting each

           -i|--subvolid <subvolid>
               subvolume id to be removed instead of the <path> that
               should point to the filesystem with the subvolume

               (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

           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.


           Path filtering

                   print only subvolumes below specified <path>.

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

           Field selection

                   print the parent ID (parent here means the subvolume
                   which contains this subvolume).

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

                   print the generation of the subvolume (default).

                   print the UUID of the subvolume.

                   print the parent UUID of the subvolume (parent here
                   means subvolume of which this subvolume is a

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

           Type filtering

                   only snapshot subvolumes in the filesystem will be

                   only readonly subvolumes in the filesystem will be

                   list deleted subvolumes that are not yet cleaned.


                   print the result as a table.

               By default the subvolumes will be sorted by subvolume ID

               -G [+|-]<value>
                   list subvolumes in the filesystem that its generation
                   is >=, ⟨ or = value. '+' means >= value, '-' means <=
                   value, If there is neither '+' nor '-', it means =

               -C [+|-]<value>
                   list subvolumes in the filesystem that its
                   ogeneration is >=, <= or = value. The usage is the
                   same to -G option.

                   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 --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

           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).

                       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:                  -


           -r|--rootid <ID>
               show details about subvolume with root <ID>, looked up in

           -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.


               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.


           -s <N>
               sleep N seconds between checks (default: 1)


       The subvolume flag currently implemented is the ro property.
       Read-write subvolumes have that set to false, snapshots as true.
       In addition to that, a plain snapshot will also have last change
       generation and creation generation equal.

       Read-only snapshots are building blocks fo incremental send (see
       btrfs-send(8)) and the whole use case relies on unmodified
       snapshots where the relative changes are generated from. Thus,
       changing the subvolume flags from read-only to read-write will
       break the assumptions and may lead to unexpected changes in the
       resulting incremental stream.

       A snapshot that was created by send/receive will be read-only,
       with different last change generation, read-only and with set
       received_uuid which identifies the subvolume on the filesystem
       that produced the stream. The usecase relies on matching data on
       both sides. Changing the subvolume to read-write after it has
       been received requires to reset the received_uuid. As this is a
       notable change and could potentially break the incremental send
       use case, performing it by btrfs property set requires force if
       that is really desired by user.


           The safety checks have been implemented in 5.14.2, any
           subvolumes previously received (with a valid received_uuid)
           and read-write status may exist and could still lead to
           problems with send/receive. You can use btrfs subvolume show
           to identify them. Flipping the flags to read-only and back to
           read-write will reset the received_uuid manually. There may
           exist a convenience tool in the future.

EXAMPLES         top

       Example 1. 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:

           btrfs subvolume delete /mnt/bar/foo

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 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 
       If you have a bug report for this manual page, see
       This page was obtained from the project's upstream Git repository
       on 2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-14.)  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
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       information in this COLOPHON (which is not part of the original
       manual page), send a mail to

Btrfs v5.16.1                  02/06/2022             BTRFS-SUBVOLUME(8)

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