I’ve come across my share of articles and tips on how to properly maintain OS X. The most alarming of them is how many people recommend apps like CleanMyMac and MacBooster. These “boost the speed of your computer” apps (on Windows especially) are known to install bloatware (essentially software whose usefulness is reduced because of the excessive disk space and memory it requires) that mess with files that should never be touched.
Onyx is often considered the must have tool for maintaining your Mac. I disagree. It should be viewed as a tool for troubleshooting and even then, I would avoid using an automated application.
Maintenance Myths
Let’s go over some steps that are often confused with troubleshooting, not maintenance.
Cache Clearing
Cache is a term that you might see quite often; for internet browsers, a cache is a saved file of your most frequently visited pages. It is meant to help load the webpage faster, rather than connecting to the site again.
User cache refers to user applications. These are meant to help applications load and run faster.
I’ve seen many people becoming concerned about the size of the user cache folder when they don’t need to be. Those files are meant to be there. Therefore, they should be left alone. The only time a specific cache should be deleted is when an application begins acting up. To do this, navigate to (~ represents your home folder):
~/Library/Caches/application_name
The application folder name is sometimes weird. For example, Apple uses a naming convention like com.apple.Spotlight for the Spotlight service.
Side effects of automated cache clearing
Fonts disabled in Font Book may become reenabled. Font Book uses a cache file to remember what you have enabled and disabled.
Notifications to approve previously-approved apps may reappear. The notification that appears when you first launch an app from a third-party source will appear again.
Startup times may be longer than before. Since the caches have been removed, your Mac needs to create all of those files again.
Repair Permissions
I know far too many people that do this on a weekly basis. The tip I have usually followed regarding permissions repair is to run it after installing a third-party software.
So what does this do anyways? The X Lab has an excellent write-up regarding the function of Repairing Disk Permissions here. To run a permissions repair, open Disk Utility (Macintosh HD/Applications/Utilities/Disk Utility) and repair permissions.
In addition to running it after installing software, this is when you should run it:
After a power outage, hard restart, or system crash.
Before installing software, particularly Mac OS X updates.
Before reinstalling OS X (without formatting the disk).
Defragmenting hard drives
Ah yes, the ever famous defragmenting of the hard drive in Windows. The only time to be concerned about your hard drive is the amount of space left. If it reaches to less than 15 GB, it is time to evaluate what files you really need. Alternatively, consider using an external drive or upgrading the internal drive (or both!).
There are third-party utilities that can defrag your hardrive but there is little benefit gained from doing so.
If you’re running into issues with the hard drive (clicking noises on a non-SSD, programs and files taking unnaturally long load times), you may have to Verify Disk using Disk Utility. To do so, open Disk Utility (Macintosh HD/Applications/Utilities/Disk Utility) and run verify disk. If issues are detected, Disk Utility will need to run the Repair Disk option which can only be done from a bootable USB with OS X on it or from your recovery partition. Macworld explains how to create a bootable USB with Yosemite (10.10).
Recommended Maintenance
So what exactly should you do to maintain your Mac? Just run the maintenance scripts. Since OSX is Unix based, it includes these maintenance scripts that clean up system logs and temporary files. There are weekly and monthly scripts that need to ran. They are usually set to execute between 3:15 and 5:30 local time. The problem is, nobody ever has their machine on at those times. So the only way to ensure that they are ran is if done so manually.
You can do so by running Terminal (Macintosh HD/Applications/Utilities/Terminal) and entering the following:
sudo periodic daily weekly monthly
You’ll be prompted to enter your password, which you will not see displayed. This is to prevent onlookers from figuring out how long your password is. You’ll know the script has completed when the Terminal prompt returns. If you feel uncomfortable doing this via Terminal commands, Cocktail offers an option to run the maintenance scripts.
Other general maintenance tips are to keep your software updated, clean off the desktop (each icon preview take up RAM and resources) regularly backup your Mac (Time Machine!).
Hopefully this article helps shed some light on this matter. As I mentioned, the above myths should be viewed as troubleshooting steps.
If there is something that I’m wrong about, please comment and let me know. Additionally, if there is anything you think users can benefit from, let me know!
Sources
The X Lab
OS X Daily
Macworld
Macrumors Forums
Mac Subreddit
AppleHelp Subreddit