How to backup remote disks with Time Machine

I quite like Time Machine, the backup solution built into Mac OSX. I also like remote network drives like iDisk or Amazon S3 solutions. Unlike DropBox however (another great service), these drives don’t necessarily store copies of their files locally, and are therefore not backed up. In the case of iDisk, the sparsebundle image IS backed up, but that’s not really what I want. I want file level access to previous revisions of files.

So, I’ve set up a cron job which runs every hour and pulls down any updates. Very simple:

rsync -a --delete --update --whole-file /Volumes/iDisk/ /Users/duane/Backups/iDisk/