commit 29e8561aaf849ff217ff37fe7ad2406e2e17e3d9
parent d0cb0c3d1ff47329425c2889cc1e1be68c31ae6d
Author: Jan Pobrislo <ccx@webprojekty.cz>
Date: Fri, 21 Feb 2014 21:28:21 +0100
more readme
Diffstat:
| M | README.rst | | | 45 | ++++++++++++++++++++++++++++++++++++++++++++- |
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/README.rst b/README.rst
@@ -38,12 +38,55 @@ local destination
Snapshot is saved directly in timestamped directory. Files for hardlinking are
looked in snapshot with highest timestamp.
-plain ssh / remote shell
+remote shell destination
~~~~~~~~~~~~~~~~~~~~~~~~
Currently unimplemented. Use daemon mode instead. See USING RSYNC-DAEMON
FEATURES VIA A REMOTE-SHELL CONNECTION in rsync manpage.
+rsyncd destination
+~~~~~~~~~~~~~~~~~~
+
+Server should expose two modules: read-only ``foo`` and write-only
+``foo.push``, where ``foo`` points to a snapshot sequence directory and
+``foo.push`` to it's ``new`` subdirectory and has ``snap.rsync.pre`` as
+pre-xfer script and ``snap.rsync.post`` as post-xfer script.
+
+You can use ``snap.genconf`` to generate such configuration snippet. If you
+use snapshot pushing and want to make the pushing machine unable to read
+snapshots back, you can use ``exclude = /[0-9]*`` in the config file to make
+only the ``.snapshot.timestamp`` files readable.
+
+The ``foo`` module is used to determine which snapshots to push (unless you
+push specific ones). Each snapshot is then in sequence written to ``foo.push``
+module. The ``.snapshot.timestamp`` file in the snapshot directory is written
+last to signify that upload is complete. After that post-xfer scripts
+hardlinks all files to a timestamped directory if it does not exist yet.
+It's important to disable the ``--in-place`` option so existing files which
+are hardlinked elsewhere are not overwritten.
+
+sources
+~~~~~~~
+
+All sources accepted by rsync are possible. It's impossible to have both
+remote source and remote destination as rsync does not implement this.
+
+things to note
+--------------
+
+The rsync option ``--hard-links`` is avoided as it requires keeping whole tree
+in memory, which may be infeasible in a large setup.
+
+Hardlinks are only kept for exact same file (path, mtime, access rights). It
+is possible to make rsync search for the same file with different path using
+the ``--fuzzy`` option.
+
+It might be reasonable to implement additional deduplication (by hardlinking
+or otherwise) as rsync's algorithms are not perfect and the implementation
+does not look outside single snapshot series.
+
+Removing old snapshots is currently left to the user.
+
todo
----
