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Mac OS X Maintenance

As mentioned in the Title box - there are pages that were written a little while ago by EZ Jim, a poster on the Apple Discussions who contributed to iSight and iChat Discussions. The words the following pages are EZ Jim's

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Mac OS X Maintenance

Mac OS X is a robust operating system, but it does require some simple occasional maintenance for best performance.

For Mac OS X 10.2.x and later, Basic OS X Maintenance involves three basic operations: (1) Permissions Repair, (2) Startup Disk Repair, and, unless you keep your Mac on and awake all night, (3) Forcing the Chrons (chronological maintenance functions). If you force your Mac to run 24 hours a day, OS X automatically runs the chrons, so you do not need to do this part of maintenance.

Permissions Repair (1) and Startup Disk Repair (2) are accomplished using your Mac's Disk Utilities application. Click the Help ("?") Button in the Disk Utility window or search for instructions in Disk Utilities > Help > Disk Utility Help.

You repair permissions using Disk Utilities on your normal startup disk, but you must start from a different disk that uses the same operating system version (10.3.x, 10.4.x, etc.) to repair your startup disk. You will cause problems if, for instance, you boot from your Panther (10.3.x.) Install CD and use its 10.3.x Disk Utility program to repair your Tiger (10.4.x) Startup Disk.

You may notice some (perhaps many) "special permissions..." messages during (1) Permissions Repair. Do not be concerned about reports of special permissions. These messages are status info that can safely be ignored if your Mac reports that "The privileges have been verified or repaired on the selected volume".

When you are using Disk Utility to repair your permissions, check the "S.M.A.R.T. Status:" to be sure it says "Verified". If "S.M.A.R.T. Status" shows a yellow or red message, your disk is failing. See Disk Utilities Help for more info on "S.M.A.R.T. Status".

I run Disk Repair (2) more than once when I do it. Click on "Repair Disk" and wait for the operation to complete. Your first disk repair, or repairs if there is significant damage, may take several minutes. Do not interrupt. Repeat if Disk Utility reports that the Disk repairs were required. Once Disk Utility reports "OK", I repeat the repair process one more time. The purpose of these multiple repairs is to assure that all sub-levels of the directory structure have been repaired. I don't know if this is really necessary, but it works for me.

Apple's term for the Chrons (3) is "Background Maintenance Tasks". See this linked document for instructions. I currently use MacJanitor, but any of the methods shown will work provided that you select one compatible with your version of Mac OS X. If you manually force the chrons with a method that does not automatically perform a permissions repair afterward, (such as MacJanitor or via Terminal commands), I suggest you do so manually.

Please note the MacJanitor does not work for Leopard. Other apps such OnyX that can also do this have different versions for different OS Levels

Performing the weekly (but not the daily or monthly) maintenance tasks, whether you do so manually or your Mac does so automatically overnight, changes some permissions. Therefore, if your Mac runs the chrons automatically overnight, I suggest you repair permissions once a week. Beyond that, how often your Mac requires maintenance depends on how, and how much, you use it.

I use these procedures once a month in normal use, and I perform them again before every major OS update. Once a month works for me, but more frequently will not harm your Mac's performance.

Using the above procedures will correct most maintenance problems. However, if you are still having difficulty, or, if you have an inquiring mind and want more info, keep reading.

If you are having trouble with your Mac and you are sure it is not related to installation of any new hardware or software, you might need more intensive OS X Maintenance. Things like slow starting or inability to boot your Mac or launch applications, missing files or folders that you have not thrown away, or inability to save settings or preferences may be indications that maintenance is in needed.

If the Basic OS X Maintenance described above does not resolve your problem, try a Safe Boot and then restart. Safe boot just forces an automated OS X disk check and repair routine. It may not help, but it is quick and easy and cannot harm anything.

When Safe Boot is done, you will again see your desktop. IMMEDIATELY do a normal "Restart" to finalize all needed actions. Do not do anything other than restart while in Safe Boot mode or you risk leaving the Safe Boot actions unfinished.

If you are still having problems, you should ask what has changed since your Mac worked correctly. If the answer is nothing but time, and if you have recently performed Basic OS X Maintenance, try the comprehensive suggestions from the Mac OS X 10.3/10.4: System maintenance FAQ. DiskWarrior, which is mentioned there gets high praise for being able to resolve many disk problems that other software cannot repair.

If you would like to start with a more basic approach to OS X Maintenance, have a look at Travis A's Regular Maintenance / General Troubleshooting tips.

Keeping adequate free space on a well-maintained OS X disk will maximize your systems stability and speed. You should occasionally check your Startup Hard Disk's free space. OS X needs a MINIMUM of 10% free space according to Apple. If you are running short on disk space, do some backup and house cleaning ASAP.

CAUTION: Manually moving or deleting files is generally a BAD idea in OS X unless you KNOW what you are doing.

CAUTION: Never, under ANY circumstances, rename your Home (user) folder unless you are a UNIX expert.

After you backup your important files, delete enough of the data files from your Home (username) Directory to allow MORE THAN 15% free space. 15% will give you some "cushion" for adding future files.

You can uninstall any unnecessary applications. Carefully follow the Applications' directions for uninstalling! Do not just trash the app unless that is what the applications instructions tell you to do.

If you edit lots of large video or other data files, you will need much more than 15% free. I like to keep my hard disk more than 50% free to allow for lots of scratch file and "Undo" step space. If you do not work with large files, you will not need to free so much additional space.

If you use System Preferences > Security > FileVault to encrypt your Home folder, you must add free space equal to the size of your home folder (check it with Finder > File > Get Info to find the size) in addition to Apple's 10% MINIMUM free space.

After you have done the backups and deleted files to give you adequate free space, apply Gulliver's Mac OS X 10.3/10.4: System maintenance recommendations. (If you are using a version of Mac OS X later than 10.1.x, you can use Safe Boot as the "fsck" utility recommended in Gulliver's first paragraph 2.)

Finally, although this is not really OS X maintenance, occasionally check your third party applications and hardware web sites for possible software, driver, and firmware updates.


Written By EZ Jim

Made on Mac
Made on a Mac®

© 2005, 2006 EZ Jim
Updated September 2006

© 2005 Ralph Johns: Edited 24/9/2005, 5/5/2006
Updated September 2006. Moved to Gargoyles Mar 2007

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