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btrfs-send(8)


NAME

   btrfs-send - generate a stream of changes between two subvolumes

SYNOPSIS

   btrfs send [-ve] [-p <parent>] [-c <clone-src>] [-f <outfile>] <subvol>
   [<subvol>...]

DESCRIPTION

   This command will generate a stream of instructions that describe
   changes between two subvolumes. The stream can be consumed by the btrfs
   receive command to replicate the sent subvolume on a different
   filesystem. The command operates in two modes: full and incremental.

   All subvolumes involved in one send command must be read-only (ie. the
   read-only snapshots and this status cannot be changed if there's a
   running send operation that uses the subvolume).

   In the full mode, the entire subvolume data and metadata will end up in
   the stream.

   In the incremental mode (options -p and -c), there can be one or more
   parent subvolumes that will establish the base for determining the
   changes. The final stream will be smaller compared to the full mode.

   It is allowed to omit the -p <parent> option when -c <clone-src>
   options are given, in which case btrfs send will determine a suitable
   parent among the clone sources itself.

   You must not specify clone sources unless you guarantee that these
   snapshots are exactly in the same state on both sides, the sender and
   the receiver.

   Options

   -e
       if sending multiple subvolumes at once, use the new format and omit
       the end cmd marker in the stream separating the subvolumes

   -p <parent>
       send an incremental stream from parent to subvol

   -c <clone-src>
       use this snapshot as a clone source for an incremental send
       (multiple allowed)

   -f <outfile>
       output is normally written to standard outout so it can be eg.
       piped to receive, use this option to write it to a file

   --no-data
       send in NO_FILE_DATA mode

       The output stream does not contain any file data and thus cannot be
       used to transfer changes. This mode is faster and useful to show
       the differences in metadata.

   -v|--verbose
       enable verbose output, print generated commands in a readable form,
       (each occurrence of this option increases the verbosity level)

   -q|--quiet
       suppress all messagese except errors

EXIT STATUS

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

AVAILABILITY

   btrfs is part of btrfs-progs. Please refer to the btrfs wiki
   http://btrfs.wiki.kernel.org for further details.

SEE ALSO

   mkfs.btrfs(8), btrfs-receive(8)



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