Server duplication with Rsync...
I am an IT administrator/manager and I oversee a network of some 35 Windows PCs and 5 Red Hat Linux file servers.
The servers are:
Proprietory Windows timekeeping
Storage With disk mirroring (RAID)
On the Storage Server I have a tape backup unit and it gets backed up via a cron job each night.
With the other 4 servers, I use Rsync to back up the important data to the storage Server. Each night at a different time each server dumps it's data on to the storage server. The Windows timekeeping server is backed up 4 times per day, so if we have a failure then we can recover very recent data.
Rsync is an amazing piece of software. Andrew Tridgell was responsible for Samba as well, and Rsync is just as excellent. I'm sure glad that he's committed to Open Source!