Dell 6100, 200 manual Why Run a Scsi Devices Test?

•Read Test

Positions the read/write heads at each block of the device for reading data and verifies that all tracks on the device can be read correctly.

•Write Test

Positions the read/write heads at each block of the device and verifies that all tracks on the device can be written to correctly.

•Eject Test

Causes a CD-ROM drive to eject its CD or a SCSI tape drive to eject its tape cartridge.

Why Run a SCSI Devices Test?

If you check the SCSI hard-disk drive to determine the amount of available space, the operating system will prob- ably report problem areas. Problem areas on hard-disk drives are common because most hard-disk drives have a small amount of space that is not usable. The hard-disk drive keeps a record of this space so that the computer will not attempt to use it. Identification of unusable disk space, unless it is an unusually large amount (over five percent of the possible total), should not be regarded as a cause for testing the hard-disk drive.

The following are the most common symptoms that might prompt you to test a SCSI device:

•A SCSI hard-disk drive fails during the boot routine.

•Seek errors are reported by the operating system or application programs.

•An error message appears on the screen stating that the computer cannot read from or write to a SCSI device.

•Data on a SCSI device is corrupted or lost; this prob- lem may be intermittent. Once saved by a program, files cannot be properly recalled.

Running the System Diagnostics 5-17