Sometimes it’s better to be lucky than smart

So, a couple of weeks ago I bought a refurbished Mac Pro from Apple. It came with a single 250GB SATA drive, with 3 open SATA bays. I had Devin send me two of our spare 250GB SATA drives from a previous project, with the intention that I would create a striped RAID set to hold my VMware Fusion virtual machines.

I popped the two disks in, rebooted the computer, and fired up Disk Utility. After formatting the two disks, I attempted to create a RAID array, but Disk Utility wouldn’t see the second disk. In the process of fooling around, I created a mirrored array and added the first new drive to it, but I couldn’t add the second drive. In frustration, I did a low-level format on drive #2; when the format completed, I was able to add it to the new volume, so I copied my files over to it and went about my business.

Technorati Tags: Mac OS X

Then came Saturday. The Finder was acting funny; it would hang with a spinning-rainbow-cursor-of-death, and one of the disks was making its shutdown sound (a slight clunk followed by spindown). When this happened, the Finder and all apps would become unresponsive. Rebooting didn’t work; the system hung at boot time. I assumed this was because of a failed boot drive. It turns out, though, that one of the two drives in the mirror set had failed; it was making the loud Clunk of Death. Once I pulled it, I was able to boot and work normally.

Moral: I got really lucky. If I had successfully created a stripe set, I would have lost about 40GB of virtual machines that would require rebuilding, taking me a day or two of work. Because I accidentally created a mirror set, I narrowly survived the loss of the bad drive… lucky me!