Mac Hard Disk Management

By Howie Fenton

What does it take to keep your hard disk running smoothly? Do you have to keep your hard disk fastidiously clean like a Felix Unger from the Odd Couple? Or do you have to become a super- sleuthing, techno-babbling, electronic Sherlock Holmes? Actually it's a little of both. In normal day to day operations you should strive to keep your hard disk clean of viruses, fragmentation and bad sectors. And on those fog ridden gloomy nights when you develop a problem you need to develop the deductive skills of a electronic Sherloch Holmes.


In your day to day work you should watch everything that's put into your computer just as Felix Unger watched what entered the apartment. He didn't want dirt dragged in and your donÕt want a virus let in. Viruses are serious. The reason viruses are serious is because the longer the are on your hard disk the more applications and files they can infect. In addition, the longer your hard disk is infected then more of your floppies get infected and could reinfect your hard disk even after disinfecting it.

The commercial antivirus programs of choice are Symantec Antivirus Utility for the Mac (SAM) and Microcom's Virex, while the public domain program of choice is Disinfectant. All have INITs (initialization programs) which are mini programs which you place in your System Folder and scan inserted disks for infections.As we will discuss later INITs are not as essential as the System Files, but some are necessary for hard disks, networks and scanners to work properly. INITs load in alphabetical order.

Another problem to watch out for is hard disk fragmentation. Unlike viruses, fragmentation is a normal function when working with a hard disk. You can think about your hard disk as containing several continuous sectors of available room. If a small file is erased and a larger file is saved, part of the larger file will go into the small space and the rest will go into the next availble space or spaces - this is fragmentation. A seriously fragmented disk is slower because the computer has to search many places for information. Excessive fragmentation can slow performance, inhibit the start-up procedure and sometimes cause a unrecoverable disk error. Disk fragmentation is most dangerous when it happens to the operating system.

There are two basic ways to deal with fragmentation. One way is to backup the entire disk, reformat it, and restore your data from your backup copy. The other is to use a defragmentation or optimizing program. Reformatting the hard disk erases the data so that the data can be replaced in consecutive blocks. It also locks out bad sectors which is discussed later.

Backing up is commonly done via tape backup or with backup programs like Fifth Generation Systems Fast Back. An important consideration, if you choose this option, is to restore your data file by file. An image backup and restoration will simply replace your data in its original fragmented structure.

For people that don't have backup devices there are utility programs which defragment or optimize hard disks without reformatting them. The popular Mac programs include Symantec Utilities for the Mac (SUM), AlSoft Disk Express, Symantec's Norton utilities. and Central Point SoftwareÕs MacTools Deluxe. An advantage of Disk Express is that it can defragment your hard disk as a background function. Therefore it can defragment your hard disk when you go to lunch - if you leave your computer on.

If you start to notice your computer performing slowly and crashing more then usual you might want to rebuild the desktop and check for bad sectors on your hard disk. Why rebuild the desktop? When you delete files the old information of the desktop map remains in the desktop file. This can be a problem if you add and delete files often.. Rebuilding the desktop eliminates this problem. You can rebuild your desktop by holding down the shift-option-command keys, as you go through the start up procedure.

Bad sectors occur in normal operations that is why hard disk manufacturers suggest reformatting your hard disk every six to nine months. Reformatting a hard disk locks out obvious bad blocks, but not borderline bad blocks. To lock out borderline bad blocks (low level format) you need to use a program that specifically searches for these blocks.

The programs of choice for this are Symantec's SUM, and Norton Utilities for the Mac.. Be warned however, this is not a procedure for the impatient. It can take hours to search for bad blocks, copy the file, erase the file written to the bad block, and lock out the bad blocks.


It is the eleventh hour before a deadline, you turn on your Macintosh, you get halfway through the start-up and the computer freezes. You try again and the same thing happens. This when you have to become an electronic Sherlock Holmes and work through the maze or possible problems. Although the problem could be hardware or software, if you don't get a "sad Mac icon" then the problem is most likely hard disk related problem. There are several possible solutions, some are temporary fixes while others are long term.

If your under a deadline and you don't have time to play detective the quickest, most obvious solution is to start the computer using a floppy disk with the System Files on it. To start up from a floppy disk you need to make a floppy disk with the appropriate System Files, BEFORE the problem occurs. .If you use a program like Fifth Generation Systems Suitcase or Master Juggler, then copying System Files to a floppy is not a problem. If you don't use Suitcase or Juggler then your fonts or desk accessories (DA's) could increase the size of the System Files beyond the size that can be copied on one a floppy disk.

Starting up from this floppy is a reliable, albeit temporary fix. Eventually, however, you will need to diagnosis and overcome the problem. If you can start up using the floppy disk then the problem could be a corrupted system file. If the System Files are corrupted then the cure is to replace the corrupted files with good files from the floppy disk.. To do this, start from the system floppy disk we created, and copy all the System files to the System Folder your hard disk. If replacing the System Files does not overcome the problem than the next possible problem could involve the INITs / CDEV's (Control Panel devices pronounced see-dev).

Similar to INITs, CDEV's are mini programs which you place in your System Folder. and load into memory during the start up. Unlike INITÕs, CDEV's are displayed at the left side of the control panel. The Ōknobs and dialsĶ to control CDEV's are accessed through the control panel. One way to inhibit the INITs from loading which can be accomplished by holding down the option - command key sequence during start up (systems before version 7), or by depressing the shift key with System 7.

If your computer starts up when you inhibit your INIT / CDEV but doesn't work when you donÕt then you either have a corrupted INIT / CDEV file or a INIT conflict. One way to diagnose a INIT / CDEV conflict is to inhibiting them from loading and replace them one by one, restarting the computer after replace each one. This is not fun.

If are using removable hard disks such as a SyQuest based drive or a Iomega Bernoulli and you can start from your floppy disk, then there is a faster way to get up and running. Copy over the corrupted System Folder from a back-up you store on the removable hard disk. This can be done by copying your System Folder (with all the INITs and CDEVs contained) to the removable hard disk, before there is a problem. In addition, remember to copy the INIT required to mount the removable hard disk (if any) to your System Folder on your emergency floppy disk.

If you add a new INIT or CDEV that conflicts with another one in your system you have to rename one of them. If the one recently added is in conflict rename it by placing a blank space or asterisk in front of the title. If you have a corrupted INIT / CDEV you need to replace it. If you donÕt have removable hard disk then you can backup all of your INITs / CDEV's on a floppy disk BEFORE there is a problem.

If that isn't the problem maybe you need to "zap your PRAM". PRAM or parameter RAM is a section of RAM that stores data such as the current date, time, and start up disk that must be correct when the Mac is turned off. If this information is corrupted then the Mac may not identify the hard disk as the correct start up disk. There are two ways to do this depending on which Mac you have. If you are using an SE, Mac II or portable then hold down the command - shift - option keys while you select the Control Panel DA from under the desk accessory menu. A dialog box will come up asking you if you want to "zap the PRAM". Say yes and restart. If you have a 512, or 128 you need to remove the battery for half an hour and replace it. After "zapping the PRAM" remember to reset the clock and calendar using the Control Panel .


If you treat your computer like Oscar Madison you will experience more frequent and more devastating crashes.

If on the other hand you treat your computer like Felix Unger or Sherlock Holmes then your problems will be less.

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