Provided by: btrfs-tools_4.4-1_i386 bug


       btrfs-subvolume - control btrfs subvolume(s)


       btrfs subvolume <subcommand> [<args>]


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


       A subvolume in btrfs is not like an LVM logical volume, which is quite
       independent from each other, a btrfs subvolume has its hierarchy and
       relations between other subvolumes.

       A subvolume in btrfs can be accessed in two ways.

        1. From the parent subvolume

           When accessing from the parent subvolume, the subvolume can be used
           just like a directory. It can have child subvolumes and its own

        2. Separate mounted filesystem

           When mount(8) using subvol or subvolid mount option, one can access
           files/directories/subvolumes inside it, but nothing in parent

       Also every btrfs filesystem has a default subvolume as its initially
       top-level subvolume, whose subvolume id is 5. (0 is also acceptable as
       an alias.)

       A btrfs snapshot is much like a subvolume, but shares its data(and
       metadata) with other subvolume/snapshot. Due to the capabilities of
       COW, modifications inside a snapshot will only show in a snapshot but
       not in its source subvolume.

       Although in btrfs, subvolumes/snapshots are treated as directories,
       only subvolume/snapshot can be the source of a snapshot, snapshot can
       not be made from normal directories.


       create [-i <qgroupid>] [<dest>]<name>
           Create a subvolume <name> in <dest>.

           If <dest> is not given, subvolume <name> will be created in the
           currently directory.


           -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.


               wait for transaction commit at the end of the operation

               wait for transaction commit after delet each subvolume

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

       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.


               print parent ID.

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

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

               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 receive operation

               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 option.

               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

           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.


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


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


       btrfs is part of btrfs-progs. Please refer to the btrfs wiki for further details.


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