I am the network administrator for an agricultural lab in Nebraska. I use BTsync to sync a file server to my home since I am responsible for taking home backup tapes weekly in case of a disaster, so instead I do this. I have a small ubuntu server at my house (about 10x8x4 inches) with a 1TB external HDD connected via USB. The file server at the lab backs up to a Freenas server in the lab each night, BTsync is running on the freenas server and the ubuntu server at my house. The initial sync was about 120GB and took 30 hours to complete but now they only sync for about 2 hours each night after the file server finishes its backup process to the freenas server. I no longer have to take backup tapes home and the data is more up to date than the tape so we would lose less data in case of fire, tornado, etc. I also see that BTsync is available for synology NAS which we have in our other locations. This is also completely automated so all I have to do is check to make sure the data is getting synced occasionally. I have been running this for about 2 months without any trouble. I keep up to date with btsync and make sure both servers are running the same version. This is by far the easiest backup I have ever done.