This Old iMac: Repairing Your Hard Drive

Last time on This Old iMac, I moaned about the lack of space on my 2011 27′ iMac’s hard drive and detailed how DaisyDisk helped me easily get a handle on what was eating up my disk space. After reading the article, Software Ambiance’s CEO, Oleg Krupnov,offered a few tips for speeding up DaisyDisk scans (A 20-minute scan is an anomaly and on older systems 4-5 minutes is the norm. On newer Macs with SSD drives, scan time is measured in seconds!).

The Hidden Items category in my original scan was overly large. Usually this should be around 3-5 GB. Anything larger could be indicative of a file system in need of repair. The best way to see what’s in those hidden files is to run DaisyDisk as an Administrator by selecting the option from the drop-down menu on the Scan button. It takes a little bit longer; but this will break apart Hidden Items so you can see what it contains.

DaisyDisk highlights drives being scanned as Administrator in purple, nice. (Photo by Anthony Karcz)

Turns out, I had a lot of old User Accounts on my hard drive taking up Admin space. Once I saved out the few files I actually needed, those got scrubbed out of the system. Yay, more disc space!

Even though I’d found a solid culprit for my large amount of hidden files, I still wanted to make sure nothing was amiss with my hard drive. Apple introduced File System Journaling back in OS X Panther to help prevent file corruption, so things shouldn’t be too bad. But I’ve been around long enough to know that five years of power outages and hard crashes creates issues, no matter what. In OS X El Capitan, repairing it is a simple one-button solution.

Open the Disk Utility (which, incidentally, you could use instead of DaisyDisk if you wanted a bare-bones look at the contents of your hard drive), select your main hard drive (though it should be selected by default), and click the First Aid icon.

The system will run through and make any repairs to system files that it needs to, cleaning up permissions and a host of other system-level fixes. If you’ve never done this, and you have an older Mac, it’s a good place to begin before you start your spring cleaning.

Between those two things, my DaisyDisk scan time went from over 20 minutes to around 15 – not exactly the target I was searching for; but better than before. Even better, I’ve managed to clear out some files I no longer needed and improved my iMac’s stability. Not bad for a few minutes of button clicking. Am I concerned that my scan time didn’t improve that much? Not really. I still have that monstrous Photo Library of mine – I’m confident that once it’s dealt with, my overall system performance will improve greatly.

Good thing that I just received a piece of hardware that’s going to help me conquer it. Next time!