I feel a little silly for just now thinking about this but here's my story and I wanted to know if I'm missing anything. For the past 2 years I've been using my Mac Mini 2009 2.0Ghz model with it's internal 120GB drive as my main always on home server and media streaming device. I've attached to it a Sans Digital TowerRAID 4 bay SATA USB 2.0 enclosure. In that enclosure I've had four 1TB drives. The enclosure is only capable of doing JBOD (just a bunch of disk) so to OS X, it sees each disk in each bay as it's own disk. I've then been using Disk Utility and making two RAID 1 Mirror sets. Since one of my 1TB drives died in the enclosure, I bought two external 3TB drives that I confirmed beforehand could be opened up and the SATA drives extracted with ease. I did so and discovered that my external 4 bay enclosure only supports up to 2TB per disk after the fact. That said, I put the 3TB drives back into their enclosures and was starting the process of setting up a new RAID 1 mirror with the two 3TB external drives when the thought hit me that it'd probably be easier, safer and all around better if I just took the two drives and made one the active drive with the "live" data on it and the other only for Time Machine backups of the "live" drive. This "should" let me get point in time recovery on top of being a backup of my data. Is there anything I'm missing that would make this less ideal to do than the Mirror I've been doing up to this point? I confess I'm inexperienced with Time Machine and realize there might be something about it that I'm not aware of that would make this a bad idea.