1BTRFS-SEND(8) BTRFS BTRFS-SEND(8)
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6 btrfs-send - generate a stream of changes between two subvolume snap‐
7 shots
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10 btrfs send [-ve] [-p <parent>] [-c <clone-src>] [-f <outfile>] <subvol>
11 [<subvol>...]
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14 This command will generate a stream of instructions that describe
15 changes between two subvolume snapshots. The stream can be consumed by
16 the btrfs receive command to replicate the sent snapshot on a different
17 filesystem. The command operates in two modes: full and incremental.
18 All snapshots involved in one send command must be read-only, and this
20 status cannot be changed as long as there's a running send operation
21 that uses the snapshot. Read-only mount of the subvolume is not suffi‐
22 cient, there's no way to guarantee that there won't be any other
23 writable mount of the same subvolume that would potentially write while
24 send would be running.
25 In the full mode, the entire snapshot data and metadata will end up in
27 the stream.
28 In the incremental mode (options -p and -c), previously sent snapshots
30 that are available on both the sending and receiving side can be used
31 to reduce the amount of information that has to be sent to reconstruct
32 the sent snapshot on a different filesystem.
33 The -p <parent> option can be omitted when -c <clone-src> options are
35 given, in which case btrfs send will determine a suitable parent from
36 among the clone sources.
37 You must not specify clone sources unless you guarantee that these
39 snapshots are exactly in the same state on both sides--both for the
40 sender and the receiver. For implications of changed read-write status
41 of a received snapshot please see section SUBVOLUME FLAGS in
42 btrfs-subvolume(8).
43 Options
45 -e if sending multiple subvolumes at once, use the new format and
47 omit the end cmd marker in the stream separating the subvolumes
48 -p <parent>
50 send an incremental stream from parent to subvol
51 -c <clone-src>
53 use this snapshot as a clone source for an incremental send
54 (multiple allowed)
55 -f <outfile>
57 output is normally written to standard output so it can be, for
58 example, piped to btrfs receive. Use this option to write it to
59 a file instead.
60 --no-data
62 send in NO_FILE_DATA mode
63 The output stream does not contain any file data and thus cannot
65 be used to transfer changes. This mode is faster and is useful
66 to show the differences in metadata.
67 --proto <N>
69 use send protocol version N
70 The default is 1, which was the original protocol version. Ver‐
72 sion 2 encodes file data slightly more efficiently; it is also
73 required for sending compressed data directly (see --com‐
74 pressed-data). Version 2 requires at least btrfs-progs 6.0 on
75 both the sender and receiver and at least Linux 6.0 on the
76 sender. Passing 0 means to use the highest version supported by
77 the running kernel.
78 --compressed-data
80 send data that is compressed on the filesystem directly without
81 decompressing it
82 If the receiver supports the BTRFS_IOC_ENCODED_WRITE ioctl
84 (added in Linux 6.0), it can also write it directly without de‐
85 compressing it. Otherwise, the receiver will fall back to de‐
86 compressing it and writing it normally.
87 This requires protocol version 2 or higher. If --proto was not
89 used, then --compressed-data implies --proto 2.
90 -q|--quiet
92 (deprecated) alias for global -q option
93 -v|--verbose
95 (deprecated) alias for global -v option
96 Global options
98 -q|--quiet
100 suppress all messages except errors
101 -v|--verbose
103 increase output verbosity, print generated commands in a read‐
104 able form
105
107 btrfs send returns a zero exit status if it succeeds. Non zero is re‐
108 turned in case of failure.
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111 btrfs is part of btrfs-progs. Please refer to the documentation at
112 https://btrfs.readthedocs.io.
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115 btrfs-receive(8), btrfs-subvolume(8), mkfs.btrfs(8)
1166.6.2 Nov 24, 2023 BTRFS-SEND(8)