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CSYNC2(8) User Commands CSYNC2(8)


csync2 - cluster synchronization tool, 2nd generation


csync2 [-v..] [-C config-name] [-D database-dir] [-N hostname] [-p port]...


csync2 is copyright © 2004 - 2017 by LINBIT Information Technologies GmbH

csync2 is distributed under the GNU General Public License. See the file COPYING for details.


This manual page documents briefly the csync2 command.

A verbose manual can be found on the csync2 homepage:

csync2 is a program for cluster wide file synchronization.


With file parameters:

Add (recursive) hints for check to db
Check files and maybe add to dirty db
Updates files if listed in dirty db
Create list of files in compare-mode
Force files to win next conflict resolution
Mark files in database as dirty

Simple mode:

Run checks for all given files and update remote hosts.

Without file parameters:

Check all hints in db and eventually mark files as dirty

-u [-d] Update (transfer dirty files to peers and mark as clear)

List all pending hints from status db
List all file-entries from status db
List all dirty files from status db
List file-entries from status db for this synchronization pair.
Test if everything is in sync with all peers.
Test if this file is in sync with all peers.
Test if this synchronization pair is in sync.
Test only this file in this sync pair.
As -T, but print the unified diffs.
Remove files from database which do not match config entries.
Run in inetd server mode.
Run in stand-alone server mode.
Run in stand-alone server mode (one connect only).
Send some messages to syslog instead of stderr to not clobber the protocol in case stdout and stderr point to the same fd. Default for inetd mode.

Exit codes:

The modes -H, -L, -M and -S return 2 if the requested db is empty. The mode -T returns 2 if both hosts are in sync. Otherwise, only exit codes 0 (no errors) and 1 (some unspecified errors) are expected.


Recursive operation over subdirectories
Dry-run on all remote update operations
Do not block everything into big SQL transactions. This slows down csync2 but allows multiple csync2 processes to access the database at the same time. Use e.g. when slow lines are used or huge files are transferred.
Open database in asynchronous mode. This will cause data corruption if the operating system crashes or the computer loses power.
When running in stand-alone mode with -ii bind to a
specific interface. You can pass either a hostname or ip address. If used, this value must match exactly the host value in each csync2.cfg file.
Init-run. Use with care and read the documentation first! You usually do not need this option unless you are initializing groups with really large file lists.
Also add removals to dirty db when doing a -TI run.
Don't mark all other peers as dirty when doing a -TI run.

-G Group1,Group2,Group3,...

Only use these groups from config-file.

-P peer1,peer1,...

Only update these peers (still mark all as dirty). Only show files for these peers in -o (compare) mode.
Add new entries to dirty database with force flag set.
Print timestamps to debug output (e.g. for profiling).

-s filename

Print timestamps also to this file.
Write a list of directories in which relevant files can be found to the specified file descriptor (when doing a -c run). The directory names in this output are zero-terminated.

Database switches:

-D database-dir or url

default: /var/lib/csync2
Absolute path: use sqlite database in that directory.
If database is not given, it defaults to csync2_<qualified hostname>
Note that for non-sqlite backends, the database name is "cleaned", characters outside of [0-9][a-z][A-Z] will be replaced with _.

Creating key file:

csync2 -k filename

Environment variables:

Directory containing csync2.cfg and other csync2 system files. Defaults to /etc.


Csync2 will refuse to do anything if this file is found: $CSYNC2_SYSTEM_DIR/csync2.lock


This manual page is a hand-edited help2man processed csync2 help.

October 2017 csync2