Increasing system stability by pruning the kernel extensions folder

Look inside your /System/Library/Extensions folder. Every file in this location is a kernel extension; a piece of software that adds on to the functionality of the Mac OS X kernel, can modify its behavior, and potentially be the source of kernel panics and other problems. At a count of 250-350 kernel extensions (they reside in other locations as well) on an average system, there's a lot of room for error.

Fortunately, most kernel extensions are clearly labeled, and you can look through the /System/Library/Extensions folder for items that match the name of any device or hardware component that is accessed whenever a kernel panic ensues.

But say you're experiencing repeated kernel panics and want to eliminate any third-party kernel extensions (those not originating from Apple) as a starting point. Fortunately, there's an easy method. Launch the Terminal, located in /Applications/Utilities, and enter the following command:

• kextstat | grep -v apple

First, this command runs kextstat to get a list of all currently loaded kernel extensions. Then it pipes the resulting output into grep, which is (in this case) set to find the inverse of all the files labeled Apple.

If you're not sure what a particular kernel extension in the resulting list is, try searching for it in Google or another engine. Usually you'll find some information about the manufacturer/developer and associated device/appicaton.

On an in-house MacBook Pro, for example, there was only one non-Apple kernel extension:

• com.iospirit.driver.rbiokithelper

This kernel extension is associated with the program Remote Buddy from IOSPIRIT.

If the kernel extensions you find via this method are associated with software or devices you no longer use, it's best to remove them. Also, as aforementioned, if you're having inexplicable stability issues, it might be wise to temporarily remove all third-party extensions then place them back one by one or in groups to isolate the problem.

Feedback? Late-breakers@macfixit.com.

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