So right now I have 2 external hard drives, a 2TB MyBook Mirror edition, set at RAID 0 so its a full 2TB, and a 1TB MyBook Home Edition. I also have three LaCie 1TB drives to back up the MyBook drives. How I back up is basically copy the contents over to the backups once a month. The problem is, using USB (my only option) takes about 24 hours per TB. Backing up 3 days a month? Not fun. Can Time Machine do this better? I still have Tiger, so can't test it yet but it seems tedious to do things my way. I would rather be able to plug them in and sync every few weeks and not have to replace every file, just the ones that changed or were added. Can this be done? I don't keep the drives connected 24/7 so it would have to be manual, and also can Time Machine back up a 2TB drive to 2 1TB drives? The are stuck in enclosures so i have to connect the 2 separately through USB, can't use RAID. If Time Machine is not the answer, is there some third party program the would not require me to re-copy every file? It would be great if I could save some time doing this.