The Project goes RAID

I alluded a few days ago to the fact that the Project has been stalled for a while because of a lack of disk space. Well, things may be about to get a little kick start. I ordered a 500 GB drive and a miniStack case from Other World Computing. In fact, I like the look of the case so much, I ordered a second one to swap my existing 300 GB drive into, so I can stack the two together. And the multiple FireWire and USB hubs that it will provide will be manna; right now I have to swap the old drive from FireWire to USB when I want to sync my iPod because the FireWire port on the external drive isn’t powered.

And the RAID part? Well, I’m considering combining the two drives together so that they form a single logical disk. Mac OS X provides the capability to create three types of RAID arrays: mirrored, striped, and concatenated. I’m thinking concatenated. A lot of the commentary on this option says that it doesn’t make sense: none of the security of mirrored and none of the speed of striped. I think the commentary misses a point: sometimes it’s just awfully convenient to not have to worry about accessing two separate volumes, for instance when trying to share music across a network or manage a large volume of digital music. Plus having the ability to add additional disks to the array without blowing it is really helpful.

Of course, making the RAID array without wiping out the data on the drive is tricky. I’ve identified two ways to do it:

  1. Create a concatenated RAID array with just one disk—the new disk, copy everything from the old disk to it, then add the second disk to the array.
  2. Use the command line version of diskutil to turn the existing disk into a RAID array without destroying the data, then add the second disk. This option is riskier—I don’t know for sure if the command will destroy the data, but this post on, which gave me the idea in the first place, suggests it should work.

The drives should be here in a week, then we’ll give it the old college try.