[CentOS] Deduplication data for CentOS?

Hi list,

is there any working solution for deduplication of data for centos?
We are trying to find a solution for our backup server which runs a bash 
script invoking xdelta(3). But having this functionality in fs is much 
more friendly...

We have looked into lessfs, sdfs and ddar.
Are these filesystems ready to use (on centos)?
ddar is sthg different, I know.

Thx
Rainer