Ok, time to organize a backup strategy involving the Drobo unit.
The idea is to have Drobo having all the data around the network copied on the Drobo unit, i.e. different machines do backup on Drobo.
I did buy a Drobo for my server.
Here a kind of review and my discoveries.
Of course the main purpose is to connect Drobo to my server, so I'm planning to use it only for Linux.
The goal is to end up with at least a couple of Terabyte of space, possibly more in the future.