I currently have an iMac with a 250 GB Hard drive. From that, I have a 250GB G-Drive set up to clone every night w/SuperDuper, as well as a 500GB My Book for Time Machine. My internal main drive is reaching its limit, and I find myself deleting a lot of media files I would have otherwise kept in an effort to conserve space. In addition, I want to re-encode my iTunes library in 256 AAC as it is in 128 AAC now (most of it was imported before the iTunes standard was switched), giving a select few albums the Apple Lossless treatment. Since my Itunes library stands at 100GB now, I obviously wont have the space for a doubling with 256 AAC. This is especially important because I want/plan to get rid of all my old physical CDs as soon as possible, so I wont have a chance to re-do my library like this again, and want to get it "right" the first time. Anyway, I want to move my iTunes library to an external, and wanted to know the best way to approach this. I had planned to get 2 1TB external drives, like these: http://www.amazon.com/Western-Digit...1?ie=UTF8&s=electronics&qid=1244164340&sr=8-1 Based on the strength of a positive Macworld review. I then planned to make one the external, and use SuperDuper again to clone one to the other each night. Data loss is not an option, and I don't want my external library to be flying solo. I didn't know about RAID 1 however, and drives that offered that option, like this: http://www.amazon.com/Western-Digit...2?ie=UTF8&s=electronics&qid=1244164523&sr=8-2 It seems it would be easier to get a setup like this, on mirrored RAID 1, saving myself desk space, the use of SuperDuper, an outlet and a port (which are running out anyway). However, is it more risky? I don't really know too much about these types of setups, but I fear that the failure of one platter in the RAID 1 set up has the potential to take down the other, since they're in the same enclosure. It "seems" to me that the dual hard setup would be safer, since they're both self-contained, but I am only speculating. What is the safer bet? What would you do? Any advice is appreciated. I used the 2 Western Digital Drives as examples, but I'm open to other suggestions if anyone has strong opinions one way or another. Cost is always a consideration, but since this drive or drives will be backing up thousands of dollars worth of physical media, I'm not going to skimp for a few dollars now at the cost of reliability.