[ Thanks to Falko
Timme for this link. ]
“This tutorial shows how to set up file synchronization between
two Ubuntu 11.10 servers with Unison. Unison is a
file-synchronization tool similar to rsync, but the big difference
is that it tracks/synchronizes changes in both directions, i.e.,
files changed on server1 will be replicated to server2 and vice
versa. “