I'd like to build three identical unraid systems and place one each at my home, my brother's home, and my father's home.  The idea would be that each household would have a large, central storage pool, and each system would sync with the others so triplicate copies of all data exist at different sites at all times. 

 

Are there current facilities to provide such functionality? 

Simplest approach: Install OpenVPN on each of the servers and then sync data via rsync.

Yes. Crashplan will do it as long as you don't need access to A's files on B or C and so on. Crashplan's backups are encrypted on the other end and I don't believe are readable except in a recovery situation using the Crashplan engine. What you would end up with is computer A with directories for B and C, each of which contain encrypted versions for the corresponding machines. I am not sure to what degree they are compressed.

 

Now if you want readable copies on each machine, p1lot's idea is probably the most straightforward.

 

Hope that helps

 

 

Thanks guys.  Simple is good.  OpenVPN it is.