UNIX for Dummies Questions & Answers

I have been experimenting with rsync as a scriptable backup option, reading various example and tips pages, including Time Machine for every Unix out there - IMHO

That page seems to describe the exact behavior I want: The ability to make a "full backup" snapshot regularly, but with rsync comparing to an existing backup and using hard links where possible to avoid using more disk space to store multiple copies of files already on the destination.

I am currently testing rsync to simply copy a small test directory on the same disk, but thus far, I have not observed the --link-dest= option to create any hard links.

Code:

$ rsync -av --exclude-from=myexcludes rsynctestfolder1/ rsynctestfolder2

This creates a copy of folder 1 into folder 2 as expected. (And, BTW, the excludes in the named exclude file are behaving correctly, but that's not the issue)

Code:

$ rsync -av --link-dest=rsynctestfolder2 --exclude-from=myexcludes rsynctestfolder1/ rsynctestfolder3

This creates another copy of test folder 1 into folder 3. Now, I would expect that since all the items needed in 3 were just put into 2 and have not changed between the two operations, most (all) of the items in folder 3 would be hard links. However, using stat to examine the files in the various folders, the identically-named corresponding files in the two backups have unique inodes and only report 1 link each, so they are obviously separately-copied distinct files in the two destinations, not the hard links I am expecting.

NB, this is all on Mac OS X 10.4.11, but this is all purely command-line; my rsync --version reports as 2.6.9 with capabilities including hard links.

Thanks for any suggestions. --JMF