Lorna, I hadn't heard of rsnapshot before. I currently use rdiff-backup instead. Are you familiar with rdiff-backup? Do you have any thoughts about the two?
rsnapshot seems awfully nice in that every file is just a 'copy-able' file to do a 'restore'. Which makes it good not only for backups, but also just for 'extra storage' (even if you have to traverse the odd hourly.0 type directories.
Whereas rdiff-backup saves more space, but keeping diff files (and in some cases reverse diffs) to know the differences that existed in old versions.