ABCs of z/OS System Programming Volume 3 - IBM Redbooks

8.24 Tape capacity - tape mount management
3480=200 Mb
Figure 8-24 Tape capacity
3490=800 Mb
3590=10,000 Mb
3592=300,000 Mb
Tape capacity
The capacity of a tape depends on the device type that is recording it. 3480 and 3490 tapes
are physically the same cartridges. The IBM 3590 and 3592 high performance cartridge tape
is not compatible with the 3480, 3490, or 3490E drives. 3490 units can read 3480 cartridges,
but cannot record as a 3480, and 3480 units cannot read or write as a 3490.
Tape mount management
Using DFSMS and tape mount management can help you reduce the number of both tape
mounts and tape volumes that your installation requires. The volume mount analyzer reviews
your tape mounts and creates reports that provide you with information you need to effectively
implement the tape mount management methodology recommended by IBM.
Tape mount management allows you to efficiently fill a tape cartridge to its capacity and gain
full benefit from improved data recording capability (IDRC) compaction, 3490E Enhanced
Capability Magnetic Tape Subsystem, 36-track enhanced recording format, and Enhanced
Capacity Cartridge System Tape. By filling your tape cartridges, you reduce your tape mounts
and even the number of tape volumes you need.
With an effective tape cartridge capacity of 2.4 GB using 3490E and the Enhanced Capacity
Cartridge System Tape, DFSMS can intercept all but extremely large data sets and manage
them with tape mount management. By implementing tape mount management with DFSMS,
you might reduce your tape mounts by 60% to 70% with little or no additional hardware
Chapter 8. Storage management hardware 491