This originally was from the old blog. I’ve reposted it with a few minor changes by request.
Make your own Drobo for cheap. Well, not exactly. But close. If you are like me your main disk drive is 3T or bigger now. You also probably have a bunch of 1T drives laying around. Some you can use for a particular manual backup of data. However you can’t really use them for automated backup because they are just all too small. Like me you may have looked at Drobos or Synology bays with lust, wishing you could take your old drives and make a backup system with them. Yet those drive bays are usually ridiculously expensive. Too much for Time Machine. 1
The alternative is to use Apple’s Fusion Drive technology. You won’t be creating an SSD/HD fusion.2 Rather you’ll be taken a bunch of drives and treating them as a single logical drive. To avoid things from getting too confused, I strongly suggest getting a multidisk bay. I used a ProBox USB3 4 bay enclosure for mine. If you don’t do that remember that if one drive goes down none of the drives will work right.3 In other words bad things happen if they aren’t all running. Trying to keep 4 disks straight when you may have several others is just asking for trouble.
- I’d never consider Time Machine a primary backup — just a “nearly good enough” versioning and backup solution. It’s just too unreliable to be a real backup. Instead I have a collection of full disk backups I rotate through and then some dated backups of particular files I automate via Python. ↩
- Although it’s pretty easy and works great. I put a 420G SSD in my 2010 MBP along with a 500GB 3.5” HD as a Fusion drive. It works fantastic. Much better than my old system of symlinking directories off the SSD to the Hard Drive. All you have to do is replace the DVD drive with a caddy that can hold the HD. ↩
- This isn’t a hypothetical. I originally wrote this post last fall. In spring one of the four disks did go down. I had to undo the Fusion drive, figure out what drive was bad, and then recreate. For this reason don’t ever consider this a primary system. Even if you use new disks. But if you, like me, use old disks laying around it’s a question of when, not if, the Fusion drive will go down. ↩