btrfs-subvolume - manage btrfs subvolumes


   btrfs subvolume <subcommand> [<args>]


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


   A subvolume is a part of filesystem with it's 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

       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

   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

   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.


   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 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 deleting 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), mount(8), btrfs-quota(8), btrfs-qgroup(8),


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