rsync 3.0 looking very promising

A little while back, I mentioned the sad state of rsync in Mac OS X. Well I’ve had a chance to test rsync 3.0 prerelease 7 and I am very pleased with the results.

To test for yourself, download the source, extract the source, cd into the extracted directory, run ./configure, run make, and then make install. You’ll find the new rsync installed at /usr/local/bin/rsync. View the man page using man -M /usr/local/share/man rsync.

Use -X for extended attributes ( and resource forks )
Use -A for ACLs
Don’t use -E, which was Apple’s flag for these as it is used for executability

Here are my test results:

Resource Fork Handling: For testing resource forks, I used to keep a copy of SimpleText around as it is all resource fork and no data fork, but a text clipping, which is also all resource fork is a great test. rsync 3 syncs the resource fork exactly the way you’d like. It retains the fork during the initial copy, and only re-copies the file if the fork has changed. This is quite awesome since Apple’s bundled rsync always copies the fork causing major speed hits even when no files have changed. I haven’t looked at the source code to see how rsync determines if the resource fork changed, but it seems efficient so far, though they may be doing checksums because using the -X flag adds time to the compare phase.

I dragged a text clipping into my source folder. I verified its resource fork using cat somefile/rsrc. I ran rsync and verified the destination’s resource fork. I re-ran rsync and no files were copied. I appended some data to the fork and rsynced again. rsync detected the file as changed and re-copied it with the changed resource fork. You can test it yourself. Using the –stats or -v option, try running Apple’s rsync, then rsync 3 and you’ll see the number of files transferred.

Metadata tests: I recently found backup bouncer, which runs a multitude of tests on metadata preservation.

------------------ rsync-3.0pre7 ------------------
This copier exited with error code 23
This copier produced log output in:
/Volumes/Dst/11-rsync-3.0pre7/log
Verifying: basic-permissions ... ok
Verifying: timestamps ...
Sub-test: modification time ... ok
ok
Verifying: symlinks ... ok
Verifying: symlink-ownership ... ok
Verifying: hardlinks ... ok
Verifying: resource-forks ... ok
Verifying: finder-flags ... ok
Verifying: finder-locks ... FAIL
Verifying: creation-date ... FAIL
Verifying: bsd-flags ... ok
Verifying: extended-attrs ...
Sub-test: on files ... ok
Sub-test: on directories ... ok
Sub-test: on symlinks ... ok
ok
Verifying: access-control-lists ...
Sub-test: on files ... ok
Sub-test: on dirs ... ok
ok
Verifying: fifo ... FAIL
Verifying: devices ... FAIL
Verifying: combo-tests ...
Sub-test: xattrs + rsrc forks ... ok
Sub-test: lots of metadata ... ok
ok

Overall it fares pretty well.

The lack of support for finder-locks (aka flags like uchg) is unfortunate. Files on the destination are simply unlocked. This solves the problem of rsync not being able to delete locked (uchg) files, but it is kind of worse because that metadata is just plain lost and a lot of old time Mac users are accustomed to using that feature since it is right there in the GUI Finder Get Info panel.

I suppose a workaround would be to find all the files that have the flag and create a transcript of them before running rsync for later re-locking.

I need to do some performance testing compared to rsyncx, but so far, rsync 3 looks good to me.