NAME

       btrfs-send - generate a stream of changes between two subvolume snapshots

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
       subvolume snapshots. The stream can be consumed by the btrfs receive command to replicate
       the sent snapshot on a different filesystem. The command operates in two modes: full and
       incremental.

       All snapshots involved in one send command must be read-only, and this status cannot be
       changed as long as there’s a running send operation that uses the snapshot.

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

       In the incremental mode (options -p and -c), previously sent snapshots that are available
       on both the sending and receiving side can be used to reduce the amount of information
       that has to be sent to reconstruct the sent snapshot on a different filesystem.

       The -p <parent> option can be omitted when -c <clone-src> options are given, in which case
       btrfs send will determine a suitable parent from among the clone sources.

       You must not specify clone sources unless you guarantee that these snapshots are exactly
       in the same state on both sides—both for 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 output so it can be, for example, piped to
           btrfs receive. Use this option to write it to a file instead.

       --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 is 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 messages 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)