Provided by: btrfs-tools_0.19+20100601-3ubuntu3_i386 bug

NAME

       btrfs - control a btrfs filesystem

SYNOPSIS

       btrfs subvolume snapshot <source> [<dest>/]<name>

       btrfs subvolume delete <subvolume>

       btrfs subvolume create [<dest>/]<name>

       btrfs subvolume list <path>

       btrfs subvolume set-default <id> <path>

       btrfs filesystem defrag <file>|<dir> [<file>|<dir>...]

       btrfs filesystem sync <path>

       btrfs filesystem resize [+/-]<size>[gkm]|max <filesystem>

       btrfs device scan [<device> [<device>..]]

       btrfs device show <dev>|<label> [<dev>|<label>...]

       btrfs device balance <path>

       btrfs device add <dev> [<dev>..] <path>

       btrfs device delete <dev> [<dev>..] <path> ]

       btrfs help|--help|-h

DESCRIPTION

       btrfs  is  used to control the filesystem and the files and directories
       stored. It is the tool to create or destroy a snapshot or  a  subvolume
       for  the filesystem, to defrag a file or a directory, flush the data to
       the disk, to resize the filesystem, to scan the device.

       It is possible to abbreviate the  commands  unless  the  commands   are
       ambiguous.   For example: it is possible to run btrfs sub snaps instead
       of btrfs subvolume snapshot.  But btrfs dev s is not  allowed,  because
       dev  s  may  be interpreted both as device show and as device scan.  In
       this case btrfs returns an error.

       If a command is terminated by --help , the relevant help is showed.  If
       the  passed  command matches more commands, the help of all the matched
       commands are showed. For example btrfs dev --help shows the help of all
       device* command.

COMMANDS

       subvolume snapshot <source> [<dest>/]<name>
              Create  a  writable  snapshot of the subvolume <source> with the
              name <name> in the  <dest>  directory.  If  <source>  is  not  a
              subvolume, btrfs returns an error.

       subvolume delete <subvolume>
              Delete  the  subvolume  <subvolume>.  If  <subvolume>  is  not a
              subvolume, btrfs returns an error.

       subvolume create [<dest>/]<name>
              Create a subvolume in <dest> (or in  the  current  directory  if
              <dest> is omitted).

       subvolume list <path>
              List  the subvolumes present in the filesystem <path>. For every
              subvolume is showed the subvolume ID (second column), the ID  of
              the  top  level  subvolume (fifth column), and the path (seventh
              column) relative to the top level subvolume.  These <ID> may  be
              used  by the subvolume set-default command, or at mount time via
              the subvol= option.

       subvolume 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.

       filesystem defragment <file>|<dir> [<file>|<dir>...]
              Defragment files and/or directories.

       device scan [<device> [<device>..]]
              Scan devices for a btrfs filesystem. If no devices  are  passed,
              btrfs scans all the block devices.

       filesystem sync <path>
              Force a sync for the filesystem identified by <path>.

       filesystem resize [+/-]<size>[gkm]|max <path>
              Resize  a filesystem identified by <path>.  The <size> parameter
              specifies the new size of the filesystem.  If the prefix + or  -
              is  present  the  size is increased or decreased by the quantity
              <size>.  If no units are  specified,  the  unit  of  the  <size>
              parameter  defaults to bytes. Optionally, the size parameter may
              be suffixed by one of the following the units designators:  'K',
              'M', or 'G', kilobytes, megabytes, or gigabytes, respectively.

              If  'max'  is  passed,  the filesystem will occupy all available
              space on the volume(s).

              The resize command does not manipulate the  size  of  underlying
              partition.  If you wish to enlarge/reduce a filesystem, you must
              make sure you can expand  the  partition  before  enlarging  the
              filesystem  and  shrink the partition after reducing the size of
              the filesystem.

       filesystem show [<uuid>|<label>]
              Show the btrfs filesystem with some additional info. If no  UUID
              or label is passed, btrfs show info of all the btrfs filesystem.

       device balance <path>
              Balance the chunks of the filesystem identified by <path> across
              the devices.

       device add <dev> [<dev>..] <path>
              Add device(s) to the filesystem identified by <path>.

       device delete <dev> [<dev>..] <path>
              Remove device(s) from a filesystem identified by <path>.

EXIT STATUS

       btrfs returns a zero exist status if it succeeds. Non zero is  returned
       in case of failure.

AVAILABILITY

       btrfs is part of btrfs-progs. Btrfs filesystem is currently under heavy
       development, and not suitable for any uses other than benchmarking  and
       review.   Please  refer  to the btrfs wiki http://btrfs.wiki.kernel.org
       for further details.

SEE ALSO

       mkfs.btrfs(8)