Comment 10 for bug 581614

Maybe your problem isn't exactly the same as mine. Maybe you really do have a problem with creating hard-links as Alexis wrote.

Have you tried what Alexis suggested in order to verify if you can create hard-links?
Try "cp -l" command on your local filesystem -> it should work.
Try "cp -l" command on your backup destination filesystem -> you will have an error.

e.g.
cd to backup area
echo hello >a
cp a b
cp -l a c
ls -li a b c
  13397 -rw-r--r-- 2 dave dave 6 2010-05-18 15:51 a
  13398 -rw-r--r-- 2 dave dave 6 2010-05-18 15:51 b
  13397 -rw-r--r-- 2 dave dave 6 2010-05-18 15:51 c

The first number is the inode number, and if the inode for a and c are not identical, then you can't create hard links

Also - the patch I provided worked for me and seemed to run ok- but it hasn't been vetted by the developers - its just a suggestion to them on one way that might fix an issue. Use at your own risk...