I have machines running two or three of the most recent versions of SL
and would like to mirror the distros making efficient use of hard links
(there seem to be very few RPMs that are in just one version).

I'm trying:

rsync -avzH --delete  \
    --exclude=sites/Fermi --exclude=archive/debuginfo \
    --exclude=archive/obsolete \
    --include='/5[2-9x]/x86_64' \
    --exclude='/*/*' \
   rsync://rsync.scientificlinux.org/scientific/ scientific/

but I'm finding that the same file in two distributions is coming over
as two different files, rather than two hard links to the same file. For
example:

> ls -il 5[45]/x86_64/SL/evolution-2.12.3-19.el5.x86_64.rpm
71805541 -rw-r--r-- 1 root root 12388735 Sep  4  2009
54/x86_64/SL/evolution-2.12.3-19.el5.x86_64.rpm
77856909 -rw-r--r-- 1 root root 12388735 Sep  4  2009
55/x86_64/SL/evolution-2.12.3-19.el5.x86_64.rpm

This leads me to believe that either I'm doing something wrong or that
they genuinely are different, but identical, files on the SL server.

Any suggestions?

Thanks

John