btrfs-send

Send a snapshot to stdout

$ btrfs send [/path/to/snapshot]

$ btrfs send [/path/to/snapshot] -f [backup.send]

$ btrfs send -p [/path/to/parent] [/path/to/snapshot]

$ btrfs send -c [/path/to/clone1] -c [/path/to/clone2] [/path/to/snapshot]

$ btrfs send [/path/to/snapshot] | btrfs receive [/path/to/destination]

$ btrfs send -p [/snapshots/old] [/snapshots/new] | ssh [user@host] btrfs receive [/backup]

$ btrfs send -q [/path/to/snapshot]

btrfs send [-v] [-p parent] [-c clone-src] [-f outfile] subvolume

btrfs send generates a stream of instructions representing a btrfs subvolume or snapshot. This stream can be received by btrfs receive to recreate the subvolume on another filesystem, enabling backup and replication workflows.
The send operation works on read-only snapshots and produces a binary stream containing file data, metadata, and structural information. When a parent snapshot is specified, only the differences (incremental send) are transmitted, dramatically reducing transfer size for regular backups.
The stream format is forward-compatible and can be piped directly, saved to a file, or transferred over network connections like SSH.

-f file

Write stream to file instead of stdout.

Parent subvolume for incremental send.

Clone source (additional reference for deduplication).

Verbose mode.

Quiet mode (no progress).

Send without file data (metadata only).

End stream after subvolume data.

Use send stream protocol version N.

Source subvolume must be read-only. Parent snapshot must exist on receive side for incremental restores. Stream is not human-readable. Interrupting send/receive may leave incomplete subvolumes. File permissions and ownership require appropriate privileges to restore. Compressed send streams require protocol version 2+.

btrfs send/receive was introduced in Linux kernel 3.6 (released September 2012) as part of btrfs development. It was designed to enable efficient snapshot-based backup and replication, similar to ZFS send/receive. The feature has been enhanced over time with compressed transfers (protocol v2) and improved performance for large filesystems.

btrfs-receive(8), btrfs-subvolume(8), btrfs(8), rsync(1)