RAID Rocks!
Submitted by mott on April 25, 2008 - 10:45
This is one of those productivity tips for a small sub-goup of Mac users: those of us with a Mac Pro (because of the multiple hard drive bays). Ironically, if you own a Mac Pro you probably know this already, which undoubtedly begs the question "Why write this entry?" Well, it was enough of an epiphany for me that I thought this may save someone somewhere some grief.
RAID = "Redundant Array of Inexpensive (or Independent) Disks"
In short, RAID rocks. In particular, "Striped RAID" for its read/write speed efficiency. In concrete terms, a RAID is a combination of two or more drives into a single volume. You can create a RAID disk set with hardware, like a RAID controller card, or software, like Disk Utility. (Or anyone, Mac Pro or not, could just buy a Drobo.)
Disk Utility offers three options for creating a RAID: Mirrored (RAID 1 - or "Scary RAID"), which duplicates the same information on two or more drives; Striped (RAID 0, or "Slightly Less Scary RAID"), which splits the information between two drives, or concatenated or JBOD ("Just a Bunch of Disks" - I'm not kidding), which saves consecutively, filling one drive and then continuing onto the next, and allows you to drop in a new drive at any time without having to reformat to keep your storage space expanding infinitely.
Now, why, you may ask, am I going on about this?
Well, I have about 1 TB of data (mostly media files) that is expanding daily. I've been having problems with time-lags in using iTunes and my AppleTV. It's too early to tell if creating a 2 TB Striped RAID 0 will solve all my problems (hair loss, hearing loss, aching knees, a "different" sense of humour...) but I can tell you this:
Copying my information from a single drive using FireWire 800 took 14 hours. To copy the same information back onto the Striped RAID I'd created took only 7 hours. If my math is correct, it looks like I've doubled my read/write speed. (14 over 7, carry the 2, add COS over SIN, and multiply by mass...)
You've read technical articles about the benefits of RAID, or the lack thereof (some pundits believe there is little or no benefit to RAID, and considerably increased risk of disk failure). I'm not taking one side or another, but so far, in my experience, RAID 0 seems pretty darned fast, and I'm liking striping.
