Currently, I have Time Machine backing up my system, along with one of my external drives. The backups are pushing the limit of the 1TB backup drive to about 800GB. Trouble is, I have roughly 2TB more space that hasn't been used yet but gets used more and more each week. I'm wondering if there's a way to get Time Machine to backup to multiple drives or am I confined to using a single backup drive? I know that within the obvious Time Machine settings, it's only possible to backup to a single drive or switch between different drives. So I was thinking there might be a trick to formatting two separate drives to look like a single drive. That would theoretically work. Any ideas?