The SCSI Bus is a wonderfully versatile bus system that allows a large variety of devices to be
attached to any computer. With this versatile bus structure there are a few things that will help
maintain trouble free operation.
The most common problems experienced with hard drives are: *Software corruption. A program
has crashed and taken with it some important information that the drive and file structure need to
operate properly. The best solution here is to use a program like “The Norton Utilities”, or a similar
product to detect if the file structure and the integrity of the files are still in tact. Running a program
like this every few hours of operation can eliminate most software corruption problems.
- Viruses. This is quickly becoming one of the most common reasons for system crashes. It
is a very good idea to use an anti-virus program to eliminate the potential damage that can
occur due to viruses. The best thing to do is to be very careful when copying programs from
friends or bulletin boards.
- Bad Blocks. Bad blocks occur when either the drive has been dropped or shaken when running
or simply when a small particle of dust has been trapped by the magnetic head and damaged a
small spot on the surface of the hard drive platter. This is often called a crash and with
it comes the realization that the file that was written on that small spot may no longer be
valid. The best thing to do is to test the drive every month or so to make sure that no bad
blocks exist. Most drive or host adapter manufacturers supply a utility that will allow you
to test for bad blocks without destroying your data.
- Defragmentation. This will not so much create a problem with drive reliability as it will
in performance. As you operate a drive and copy, erase, and recopy files to it, you create
fragmentation. In other words the drive will copy files into whatever area is available on
the drive, even if that area is not contiguous. This fragmentation causes the heads to have
to move farther and take longer than they would if the file was contiguous. Defragmentation
programs are available and are part of most good drive maintenance programs like Norton
Very similar to hard drive, removable drives have an added problem. Dust contamination.
The best preventative maintenance is to operate these drives in a clean environment. Never
leave the cartridge inserted in the drive when not in use and always store the cartridges in
their protective carriers. There are also cleaning kits available that allow you to clean
and maintain the heads. These should be used as recommended by the manufacturer and most
often in situations where dust is a problem.
Optical drives are very similar in operation to removable drives, but you have the added
advantage of being able to clean the cartridge. Cartridge cleaning kits will remove all
unwanted dust and bring the cartridges back up to new specs, but be careful not to over use
the cartridge cleaner. You can physically inspect the cartridges for dust by opening the
protective sliding window on them. DO NOT TOUCH THE PLATTER.
Tape drives have two areas that are very important to maintain. The tape itself is only good for so
many copies, and its shelf life is usually limited to a few years. The best thing to do with archives is
to recopy them to new tapes after a couple of years. The tape mechanism itself is also an area
where cleaning is imperative for proper operation. Most tape drive have capstan cleaning kits
available, and these should be used periodically.
Scanners do not need as much maintenance as hard drives, but there are some things you can do to
guarantee good performance. The simplest thing to remember is that the glass does get dirty after
time and must be cleaned to guarantee a good quality scan. Simply use Windex or other glass
cleaner to maintain the cleanliness of the glass.