I had a couple of people email me on my backup article (thank you all for the links and feedback!), and that led to a few more quick thoughts.
Is there significant advantage to Firewire over USB 2 for a backup drive?
Firewire is faster. USB is slower, but the drives are less expensive.
Apple left off the firewire port on the new Macbook. There have been indications for a while that they’re starting the shift away from Firewire. What that implies for now is that any external drive you buy should have a USB interface so as to avoid long-term compatibility issues. That’s not a problem for most drives, but it’s something to be aware of.
I normally run my backup drives via USB now for a simple reason: I can plug them into a USB hub. If nothing else, it’s one less thing to plug in (not such a big deal for macpro, bigger deal for laptop). And it saves me having to think about buying a firewire hub as the drives multiply.
Firewire has target disk mode, but Apple’s also indicated it’s future is limited to the future of firewire. Apple seems to be thinking that the future is USB3, high speed wifi (N speed) and to a lesser degree gigabit ethernet. I’m going to be curious if they start including an eSATA interface, but I think if they were going to, we’d have seen one by now.
As long as you buy external drives that are USB2/Firewire400, you’ll be fine. No need to spend more for Firewire800 for a backup drive, the extra performance is more or less wasted except for the initial backup, and who cares if the initial backup finishes at 3AM instead of 7AM while you’re sleeping?
This drive to me is the sweet spot for archival backups. I’ve used the drive casing and it’s less expensive than heavier duty enclosure I recommended on my blog (only about $40 per drive over the raw disk unit). I’ve used them, they’re nice and reliable. the 1TB is a lot cheaper per gigabyte than the 2TB drives, so if you can use them, I would for now. Buying down a generation never hurts.
(FWIW, a little birdie I trust told me to not trust the 1.5TB drives, that entire generation, according to them, are going to be less reliable than the 1′s or 2′s. I haven’t seen any data to back this up, but given who they work for, I trust them enough that I’m avoiding using them. I wouldn’t freak and replace one, but I’d also plan on retiring them earlier than I might otherwise)
Why the recommendation of that Mercury Elite drive? I’m trying to understand the price-performance-reliability issues here. The Mercury you cite runs $160; Newegg, as just one sample, has Hitachi and iomega external drives, retail, USB 2.0 (or “Turbo USB 2.0″?), 1TB, at $90.
I’ve used them and found them reliable. If you have another brand you like and trust, be my guest. To a good degree, these are commodities, but I like to make sure I have a high quality enclosure and then upgrade the drive mechanisms over time rather than replace the whole thing. Some of them, honestly, cheap out on the interface and/or power supply, and some can run really hot under load (or really hot, period), which reduces reliability and lifetime. The OWC enclosures are well engineered from what I’ve seen and I have enough history with them to know that the enclosures rarely fail, so I trust recommending them.
But really, whatever works for you, but an unreliable disk enclosure can make your life hell and be more likely to die early in its lifetime.