Macs and Failing Hard Disks - an early detection tool
The other day I was sitting at my desk when I started to hear a faint clicking sound. I pushed the noise out of my mind for a while and continued to work on the task at hand. Before long the clicking started to get louder and louder; it was clearly a consistent mechanical noise and was coming from under my desk, right where my Mac Pro is parked.
I popped my head down there and sure enough, it sounded like one of my 4 hard drives was starting to go. Usually if you hear a clicking sound coming from a hard drive its demise is imminent. I blasted out a quick note about this on Twitter and my friend Ast recommended that I try running SMART Utility to see where the problem was.
SMART Utility for Mac scans the internal hardware diagnostics of a hard drive to quickly determine its health. Using the data collected on the hard drive itself as well as a custom algorithm it can help predict when a hard drive is starting to have problems and may need to be replaced. It's like an early warning system that can give you a chance to pull the data off a drive before it's too late.
I pulled SMART Utility down and ran it and sure enough a Growl warning popped up:
When I took a look at the main SMART Utility screen there was a failing drive:
My Backup drive was having some issues: 375 errors and a reallocated bad sector. This 1TB drive is my primary backup for Time Machine; with that drive potentially compromised I started to panic. With all the documents, photos and digitized home video I've collected over the last 20+ years I was worried if one of my primary drives went down I'd be in serious trouble.
Fortunately for me I had an additional drive that I kept in my Mac Pro to serve as a spare. SMART Utility recommended that I replace the drive so I reset Time Machine to point at my spare drive and let it run, backing up the drive overnight.
The next day I shut down the Mac Pro, preparing to pull out the bad drive. It was only after I powered down my Mac that I realized I could still hear that clicking sound that started this little adventure. How was the drive clicking if it didn't have any power?!?
Well, it turns out it wasn't one of my drives that was doing the clicking; it was an older UPS that was also parked right next to my Mac Pro. The fan in it had started clicking—that was the sound I was actually hearing. I proceeded to kick the UPS until it stopped clicking.
(No, really, I did. Kicked it like a soccer ball. It ended up getting quiet for about 10 minutes too. Ultimately I ended up having to replace it anyway. No nasty comments from the People for the Ethical Treatment of UPSs, please.)
An Important Lesson
While the clicking sound wasn't actually the problem it did prompt me to test my drives. Had I known that a tool like SMART Utility was out there I would have bought and run it a long time ago. Sure, the drive SMART Utility identified hadn't completely failed yet and is technically still serviceable. That said, the data I have is far too important to store it on a drive that shows signs of having problems.
SMART Utility is a nice little app, can diagnose all of your drives in just a few seconds and costs $25. Highly recommended.
Oh yeah, if your drive starts to make a clicking sound I wouldn't recommend kicking it until it quiets down. That's only something you do with a balky UPS. Got a tip for keeping your hard drive healthy? A utility you recommend for ensuring it's safe? Drop a note in the comments.