XO Wave: Mac OS X Maintenance for Audio and Video Users

Generally speaking, Mac OS X requires very little maintenance. However, don't let that fool you into ignoring maintenance completely! It's especially important that audio and video folks perform occasional maintenance to keep their systems running smoothly. Indeed, subtle problems with your system can make it difficult to record music reliably and can suck up a lot of performance. Here are some easy tips for keeping your system in shape.

First: A Warning

Most of the suggestions here involve altering your hard drive in ways that could be catastrophic if something goes wrong. That means you should make sure to take precautions, including regular backups. One free tool for making full, bootable backups of your system is called Carbon Copy Cloner; another (shareware) tool is SuperDuper!.

We should also say that although we have tested and reviewed the advice in this document, we do not necessarily follow all the advice ourselves, so be sure to think for yourself while performing these actions. Why don't we follow all our own advice? Well, at XO Audio we keep all data files on a UNIX file server; if a workstation gets flaky, we just wipe the drive and reinstall, and all the data is safe on another machine. It's an old habit from when I was a Windows admin, but it works well with a Mac, too, though it's definitely overkill. Installing Mac OS X and updating is much faster and requires much less work than Windows, so if your machine is getting really flaky, you can always skip all the steps below and do a clean install. Obviously, you'll need a safe place for your data first!

Check Your System

Before we get our hands dirty with cleanup tasks, make sure your system is actually up to whatever tasks you require of it. Are the CPU and hard drives fast enough? Does the RAM work? Most overlooked of all: Do you have enough RAM?

Checking that your hardware works can be done with a simple tool like TechTool Deluxe which comes with many AppleCare plans. You can check the SMART status of your drive in the Disk Utility app that came with your computer. The SMART status of your drive tells you if the drive has detected any problems. Generally these problems cannot be corrected, so if the status is anything but "Verified", be sure to back up your data and replace the drive. If you'd like a more obvious monitor for SMART status, check out the free SMARTReporter menu item.

Knowing if your hardware is up to your task depends on the specific task, of course. For A/V work, you'll need a fast CPU (or two or four), a large fast hard drive, and most important, lots of RAM. In the old days, when your system ran out of RAM, it told you, and you usually had to assign more memory to the app or quit some other applications to get the one you needed running. Nowadays, when the system runs out of RAM, it uses the hard drive, which is convenient but slow. If your system is slow, quitting applications my help, but quitting applications is not an efficient way to spend your time (especially since you will probably end up waiting for them to re-launch soon), so you should consider spending money on a RAM upgrade. Anecdotal reports are that Macs with 2gb RAM spend much less time showing the "wait" color wheel than lesser systems, and 2gb RAM is generally reasonably priced.

Repair Disk Permissions

Sometimes when software is installed or updates are run, the permissions of important system files may become damaged. This can affect performance of your system and may even cause crashes. To fix permissions problems with most Apple software, use Disk Utility in the Utilities folder of the Applications folder. Select your boot drive and click the Verify Disk Permissions button. Disk Utility will then do all the hard work. Note that this is a very specific fix for specific permissions problems; it is not helpful as a general cure-all.

Run Maintenance Scripts

If your computer is normally off or asleep at night, certain scheduled maintenance tasks won't run. Much of this has been fixed in recent releases of Mac OS X, but it can still be an issue. OnyX (see sidebar) is a great free utility to can run these maintenance scripts at other times. If your machine is asleep or off at night, it's a good idea to use OnyX or a similar utility to run them manually once in a while.

Empty Caches

If your drive is getting full or performance is sluggish, you might have a full cache somewhere. Caches contain data that Mac OS X stores because it thinks it might be needed again soon. For example, your drive could full of images and movies from web sites you visited, which you will never visit or watch again. Because it is not not necessary to store all this information, you can safely delete it and reclaim some of that space. You can delete the files by hand (in /Library/Caches/ and ~/Library/Caches) or use a free utility such as OnyX (see sidebar).

Repair Preferences

Preferences are stored on your system in various places. If the preferences files get corrupt for some reason, it's possible that some applications could crash when attempting to read or write their preferences. This is a much less common problem than it used to be, but it's easy enough to prevent: you can use Preferential Treatment, a free AppleScript designed to find and fix these problems. Note that Preferential Treatment may need to be run once for each user on the system.

Repair File Systems

It's possible that after using your Mac for a while, one or more file systems may get corrupt. This could be catastrophic, though Apple's HFS+ file systems (especially the journaled variants) are quite robust. You can use Disk Utility to check and repair all file systems except the one you boot from; to fix your boot file system, boot from your Mac OS X Install CD or DVD and run Disk Utility from the menu. Note that the command-line fsck program uses the same techniques to check and repair file systems as Disk Utility.

Defragment

If your drive has plenty of free space, Mac OS X can generally keep things tidy without any assistance. However, if your drive is close to full, or if you work with lots of large files (such as audio and video files), disk and file fragmentation can be a serious problem. You can use the free utility ShowVolumeFragmentation to determine if defragmentation is necessary. We have not evaluated any defragmentation utilities, so we can't recommend one at this time.

Keep Your Desktop Clear

If you have performance trouble, try removing some of those files that are cluttering up your desktop. Each desktop icon is apparently managed as a special window by the Finder, and a large number of windows can waste a considerable memory which could be used for more important things.

Reset Safari

If you have trouble with Safari, including poor performance or crashes, you may want to reset it by selecting Reset Safari from the Safari menu. There is some risk associated with this -- you may loose bookmarks and other info, so you should back up anything important first. If you are looking for something less drastic, you might first try emptying its cache by selecting Empty Cache from Safari's File menu.

Check for Hyperactive Processes

If you have trouble with a particular app or your whole system seems sluggish, it's possible that a rogue application or system task is being too demanding of the hard drive, CPU, or memory. Mac OS X has a handy utility called Activity Monitor that you can use to monitor these things. If you find a program hogging some resource, quit that program if you can. If you don't recognize what you see in the Activity Monitor, you may have to do a little Googling to find out what it does and if it's safe to "Force Quit" the program.

If you see mds or mdimport working hard, don't panic, these are the programs that build and maintain your Spotlight database. It's possible they are just doing normal indexing, so you should give them some time to do their work. If the problem persists, however, there may be a problem with your database. If simply rebooting doesn't solve the problem, Randy B. Singer suggests the following procedure:

...you can easily rebuild your Spotlight database by opening System Preferences, choose the Spotlight panel, click on the Privacy tab, and drag your main drive's icon into the Privacy window. Now drag your drive's icon out of the Privacy window and back out onto the desktop. This will cause the Spotlight database to be deleted and automatically rebuilt. (You won't be able to use Spotlight while its database is being rebuilt.).

Clearing the Spotlight database can also be done by Onyx (see sidebar). Note that while the database is being rebuilt, mds and mdimport will have to do some hard work for a little while to rebuild the database, so it's normal to experience slowdowns while that's happening.

If you have files which change a lot, and which you don't need Spotlight to search (such as Eudora mailboxes, which can be searched faster within Eudora), consider adding the folders containing these files to Spotlight's Privacy list, so Spotlight doesn't waste time indexing these files.