[rdiff-backup-users] Does rdiff-backup unlink before updating target files? (for pooling)

[dme26-a4]

Hi all,

Sorry if this has been answered - the rdiff-backup wiki isn't working for 
me at the moment (no response from the server). I couldn't find any posts 
answering my question on this list.

As per the subject line, I'm keen to pool storage on a central backup 
server across backups from multiple machines (vaguely a la BackupPC). Say 
I had run rdiff-backup from /usr on two client machines with target 
directories b1 and b2 on the server respectively.

Were I to write a script that checksumed (and then full-compared files) 
across b1 and b2 and hard-linked those files that were identical, would I 
be at risk of having the next rdiff-backup from b1 ever modify files as 
seen from b2?

PS I'm very pleased with rdiff-backup - particularly the diffing within files.