Josh Babetski : Quixotic Bravado

I Bought a Drobo! Now What?

My external back-up drive died… sorta. Something’s hosed on it and my Mac will only mount it as read-only with stern warnings to copy it and try and reformat. Sometimes it will only mount temporarily and then act like I yanked the USB cable out without ejecting. Ahhh…technology. Fortunately, the drive only contains back-up information that exists elsewhere.

All hard drives fail, it’s just a matter of when. In order to create more redundancy, I did some homework and bought myself a Drobo. It allows the mixing and matching of different-sized hard drives and keeps data redundantly stored on each drive. If one fails: just swap it out. Need more storage? Add another drive or replace an exisitng drive with a larger one.

On a related side note, I got a great deal on the Drobo at B&H Photo and Video: $349.95 after rebate. I’ve bought quite a few things from them in the past and highly recommend them.

On the old back-up drive, it was separated into multiple volumes to separate back-ups for Time Machine and SuperDuper from everything else. Time Machine, by default, will fill up whatever drive you assign it; SuperDuper, in order to be bootable, needs its own volume as well.

The challenge with the Drobo is that it’s not a fixed size disk since you can continue to add drive space. By creating volumes (or partitions), you’re fixing that capacity and changing them involves reformatting, which erases all the data, and you have to start all over. Now of course, Mac OS X supports partition resizing, but Drobo doesn’t support it and advises against it.

I did however find a few references to using a .sparseimage for each of the back-up “volumes” needed. This would allow the Drobo to just be one large flexible volume and both Time Machine and SuperDuper would still be able to function normally. Erik Barzeski’s post: “Formatting the Drobo for Time Machine Backup” is the best write-up I found on using .sparseimage with Drobo. I was leaning in this direction, but then Dave Nanian, author of SuperDuper, offered to lend some feedback on the optimal set-up via Twitter. I posted to the SuperDuper forums (”SuperDuper Set-up with Drobo: .sparseimage vs. partitions“) so the info could be useful to others and Dave gave some good reasons to partition the drive instead.

So that’s what I decided to do. My next post is a step-by-step of: “My Drobo Set-up for Time Machine and SuperDuper on Mac“.