While reading through one of my regular industry papers I
two copies of a directory structure in different locations, there is a massive
advantage held over simple tools like rsync which is the ability to update
changes made to both structures (so long as there is no conflict).
We have an ongoing CRM project which requires extensive data
synchronisation over many sites, this has proven to be a bit of a nightmare with
complex scripting based around rsync. It
will be interesting to see if Unison can simplify the process.