You might also look at rsync. But the new tool might be omirr:
The kernel generates information about which files are changed
and an externel daemon uses that information to update the files
on several servers based on timestamp of the files.
You can change files on any machine and all others are updated.
Kernel-Support is integrated into 2.1.43.
I have looked at the omirr source. Error handling is not the best
so I decided not to install it on my machine. (Though it might run
I have uploaded omirr to ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/net-source/
Florian La Roche