Protect Your Mac with Preventative Maintenance: OS X Repair and Cleanup

It seems inevitable: you've had your Mac for a few years now. It used to be clean and pristine, chugging along happily and zipping through that PDF or web page. Now it has slowed to a crawl, and its surface is smudged and dusty. Do you really have to upgrade to a new machine?

The answer is a resounding no. Break out a dustcloth and computer polish to restore the exterior luster. As for the insides, while new programs and new computers will outclass your old one, you can restore a lot of performance without even bothering to upgrade (if you're interested in boosting performance through hardware, check out "Nine Old Computer Uses"). Here's how to make your Mac run like the day you bought it.

* Back up your files: In any of the steps below, and especially as your Mac gets older, you want to be backing up your files. OS X's included backup utility, Time Machine, is a great "turn it on and forget about it" solution for most users, but there are a multitude of backup utilities out there (or you could just do it manually). Having your content saved on another hard drive is good, but to be extra safe burn copies of your most important files to DVD-RWs; that way, you can reuse just a few discs to continually make more recent updates of your critical documents.

It's important to back up on general principle, but as Macs get older there comes a greater chance of mechanical failure. On Macs with hard drives (not the solid-state flash drives of some newer models like the Macbook Air) your data will be the first thing to go if a drive fails for whatever reason. Sure, you could fork out a lot of money for data recovery, but it's far cheaper to replace the hard drive and import your old data from a good backup. You won't regret the preventative cost. Secondly, many of the following steps have the slight chance of causing some issues, so making sure you have an old copy of your system to boot from or all your data to migrate in a worst case scenario is a good computing practice (see the final note).

* Upgrade: Make sure you are running the latest software versions. Generally, new versions can improve performance and stability. For Apple applications, go to the Apple menu and click "Software Update" to see what new software can be installed.

* Clean house: Optimally, you want your hard drive to have at least 10-20% of its capacity free at any given time. Filling your drive to the brim can cause performance slowdowns and issues. Backing up old movies or unused documents to another drive is an easy way to reclaim space. If you are an audio-visual creator, deleting old project files, especially movie projects, can instantly reclaim gigabytes of space. If you set up a consistent and clear file-naming and folder hierarchy, you'll be better able to see what's old and where you have placed all your files; being tidy is a virtue even on a computer. One way of reclaiming disk space is to use Monolingual, which will delete language resources you never even knew were on your computer (1).

* Disk Repair: To prevent hard drive failures or other problems, you should do basic disk verification and repair every so often. OS X includes Disk Utility for this very function. Find it under Applications > Utilities. Here, you can select your hard drive (or drives, if you have multiple ones) and click "Verify Disk" to make sure there are no obvious issues. If need be, you can boot from your OS X installer disks to effect basic repairs. Also in Disk Utility, you can verify and repair permissions (2). While you don't need to know exactly what permissions are, making sure they are verified and repaired can prevent some OS X problems.

* Clean Caches: Caches are designed to make your computer run faster, but over time and operation your Mac can accumulate a clutter of unused cache files, old log files and other "junk". In a recent cleaning, for example, I found that Safari had accumulated more that 500MB of mostly-worthless web preview images. To clean out these files, you can use the free OnyX or CleanMyMac (shareware, $30). OnyX is largely automated and cleans things invisibly. CleanMyMac runs a full check and shows you each and every cache, log, and file that you could do without. The free version of CleanMyMac only allows you to clean 500 MB worth of cruft, but you can use it to manually find file trees for the caches and delete them yourself even after the other trial features have expired.

* Defragmentation: Defragmenting your hard disk is not something every user will have to do; in fact, OS X makes sure users will have to do it as little as possible. Ideally, a file is stored on your hard disk as bits written in contiguous sections; over time, however, files might be scattered across the hard disk. Opening these files takes longer, and over time your system may slow down. This is especially true for video editors, who are routinely editing and replacing files with very large sizes. The easiest solution to defragmentation is wiping the hard drive and reinstalling the operating system, but it's a pretty drastic step. The other choice is "defragging" the drive, moving the pieces back next to each other. The best app I've seen for this is iDefrag ($30, upgrade for $15). Not only does it show you what segments of your disk are fragmented, but it can rearrange your file systems to ward off defragmentation in the future (3). You can download a copy of the program to run your own test and see how fragmented your drive is before you buy.

* When all else fails: For whatever reason, you may have persistent software issues that won't go away, or your files are becoming unmanageable and performance is failing. If the above steps are not helping enough, you can erase your disk, reinstall OS X, and add back only the applications and documents you know you need. Before you do, make sure you have a Time Machine backup or another copy of your system in case things go bad; you can use the free CarbonCopyCloner to create a bootable image of your system on another disk.

Once you've reinstalled OS X, go to Software Update and make sure your system is up to date. From there you can drag over your custom files and applications. A fresh start like this can be a hassle, so you can do yourself a favor by following the optimization steps above first. If you try and do it every month or two, you will keep your Mac happy and fast, and a happy Mac means a happy user.

References
* (1) "Frequently Asked Questions: Monolingual". Sourceforge.net. Retrieved January 7, 2011.
* (2) "Resolve Startup Issues and Perform Disk Maintenance with Disk Utility". Apple Support. Retrieved January 7, 2011.
* (3) "iDefrag Review". Macworld UK. Retrieved January 6, 2011.

Related and Referenced OS X/Mac stories by David Fuchs: "Ten of Apple's Biggest Failures" / "9 Old Computer Uses" / "Essential Free OS X System Utilities" / "Essential Free OS X A/V Apps"