Укажите собственный порт SSH при использовании rdiff-backup.
rdiff-backup использует стандартный порт SSH при подключении к удаленному хосту.
$ rdiff-backup --print-statistics ~/Projects/personal/ rdiff-backup@backup.example.org::/rdiff-backup/repositories/personal
ssh: connect to host backup.example.org port 22: Connection refused Fatal Error: Truncated header string (problem probably originated remotely) Couldn't start up the remote connection by executing ssh -C rdiff-backup@backup.example.org rdiff-backup --server Remember that, under the default settings, rdiff-backup must be installed in the PATH on the remote system. See the man page for more information on this. This message may also be displayed if the remote version of rdiff-backup is quite different from the local version (2.0.0).
См. Страницу руководства, чтобы узнать, как указать дополнительные параметры подключения.
$ rdiff-backup --print-statistics --remote-schema "ssh -C -p 2222 %s rdiff-backup --server" ~/Projects/personal/ rdiff-backup@backup.example.org::/rdiff-backup/repositories/personal
--------------[ Session statistics ]-------------- StartTime 1599393121.00 (Sun Sep 6 11:52:01 2020) EndTime 1599393121.48 (Sun Sep 6 11:52:01 2020) ElapsedTime 0.48 (0.48 seconds) SourceFiles 11 SourceFileSize 10543 (10.3 KB) MirrorFiles 1 MirrorFileSize 0 (0 bytes) NewFiles 10 NewFileSize 10543 (10.3 KB) DeletedFiles 0 DeletedFileSize 0 (0 bytes) ChangedFiles 1 ChangedSourceSize 0 (0 bytes) ChangedMirrorSize 0 (0 bytes) IncrementFiles 0 IncrementFileSize 0 (0 bytes) TotalDestinationSizeChange 10543 (10.3 KB) Errors 0 --------------------------------------------------
Как видите это достаточно просто.