Operating In Harsh Environments; Mm Data Cartridge Erasure; Tape Cartridge Data Capacity - IBM R30 Operator's Manual

increased if 4 mm tape cartridges are operated, stored, or shipped outside the temperature
or humidity ranges shown in the following table.
Before using a cartridge, always let it adjust (acclimate) to the operating environment. Do
this by placing the cartridge with its container in the operating environment for as long as it
has been away from this environment or for 24 hours, whichever is less.
Acclimation is necessary for any data cartridge that has been exposed to a different humidity
environment or a temperature change of 11 C or 20 F or more.
Temperature
Relative Humidity
(non-condensing)
Maximum Wet Bulb

Operating in Harsh Environments

The 4 mm tape drive is ideally suited to streaming operations, as opposed to tape
movement operations involving multiple stop/starts and random searches. When the tape is
used for frequent stop and start operations, streaming movement is beneficial and should be
used whenever possible. This can be accomplished by ensuring that any save or restore
operation is the only active operation performed by a device connected to this SCSI I/O
controller.
Any tape that has been used outside the ranges specified in the previous table for an
extended period of time (50 passes in 40 hours of nonstop operation) should not be used as
an archival tape. Exposure to the environment deteriorates the magnetic and physical
strength of the tape. Do not store important data on a tape that has been used outside the
specified ranges; transfer the data to a new tape for reliable archiving.

4 mm Data Cartridge Erasure

Most bulk eraser devices do not have the capability to erase 4 mm data cartridges. To
properly erase an 4 mm data cartridge with a bulk eraser device, the erasure rating must be
at least 2000 oersted.
The 4 mm tape drive erases residual data before writing new data on the data tape.

Tape Cartridge Data Capacity

The 4 mm tape cartridge capacity is defined as the amount of data that can be stored on the
cartridge. The following variables affect the amount of data that can be stored on a tape
cartridge:
Size of the data file
Number of file marks per file
Compatibility mode (2GB or 4GB)
Media rewrites
Operating Ranges
16 C to 32 C 5 C to 32 C
(60 F to 90 F) (40 F to 90 F)
20 to 80%
26 C (79 F) 26 C (79 F)
Storage Shipping
–40 C to 52 C
(–40 F to 125 F)
20 to 80% 5 to 80%
26 C (79 F)
Using the CPU-Media Enclosure
2-37