IBM 7013 J Series, Operator'S Manual

Page: 49 / 297

Using the System Unit
2-17
Setting the Write-Protect Tab on 8 mm Tape Cartridges
Setting the write-protect tab on a tape cartridge is necessary so that information is not
accidentally lost. When the write-protect tab of a tape cartridge is set (window closed),
information can be read from the tape, but cannot be written to it.
The window on the tape cartridge controls write-protection as follows:
Window
Closed
Window
Opened
Tape is Write-Protected
Tape is NOT Write-Protected
Performance
The 8 mm tape drive employs sophisticated error recovery techniques to protect your
valuable data. When the drive reports an irrecoverable error, it has reached a point where
further retries may only damage the tape and other actions must be taken.
Under the best of conditions, an irrecoverable data error should occur no more frequently
than once every 4 years on a drive, assuming a 1GB back up 6 times a week. However,
tape cartridges that have been damaged, exposed to environmental conditions outside of
the recommended range, or worn out can greatly increase the frequency of irrecoverable
data errors.
Also, a drive that has not been regularly cleaned or that is worn out can contribute errors.
The environment that the drive and media operate in is a major contributor to the reliability
of the recorded data. A good environment will enhance the reliability, while an environment
that does not comply with the recommended limits may cause lost saves and damaged
media to occur.
It is possible, however, to have other influences (power surges, or a dust particle, for
example) which cause a transient error that cannot be duplicated. Such transient errors
should be very infrequent, and repeated occurrences should be further investigated to
locate the cause.
Usage
For those customers with more than one computer system, the 8 mm tape drive is designed
to support data interchange between systems. However, transporting the cartridge between
two systems not within the same environment could cause permanent damage to the
cartridge and resulting loss of data if precautions are not observed.
These precautions include:
•
Careful handling
•
Proper position of the cartridge (it should be kept on its edge)
•
Always keeping it within its clear plastic dust cover
•
The environmental limits recommended for the media should not be exceeded.
If the cartridge has been stored in an environment different from the drive, the cartridge
must be acclimated to the new environment before use. Follow the instructions included
with each new cartridge.