Using the Jungle Disk Workgroup edition, we setup the backup to run overnight. The first backup may take several days, but once this is complete subsequent backups are very efficient, as only the changed parts of files are transferred.

Data can and should be encrypted before it is backed up. There is some discussion around the legalities of storing clinical data off-shore, so we do suggest that you take advantage of the built in encryption that means your data cannot be read by anyone without your passphrase.