Your planning strategy must include consideration of multiple media formats and a choice of cartridge system tapes. The TCDB provides the tape device selection information (TDSI) that determines the data class attributes assigned to a volume. Depending on the IBM subsystems, available features, and interchange requirements between stand-alone and library-resident tape drives, you should include the following multimedia considerations:

1. Should data compaction be used?
2. Does the tape subsystem write in 18-track, 36-track, 128-track, 256-track, 384-track, EFMT1, EFMT2, EEFMT2, EFMT3 EEFMT3, EFMT4, or EEFMT4 format?
3. Does the tape subsystem use IBM Cartridge System Tape, IBM Enhanced Capacity Cartridge System Tape, IBM High Performance Cartridge Tape, IBM Extended High Performance Cartridge Tape, IBM Enterprise Tape Cartridge, IBM Enterprise WORM Tape Cartridge, IBM Enterprise Economy Tape Cartridge, IBM Enterprise Economy WORM Tape Cartridge, IBM Enterprise Extended Tape Cartridge, IBM Enterprise Extended WORM Tape Cartridge, IBM Enterprise Advanced Tape Cartridge, IBM Enterprise Advanced WORM Tape Cartridge, or IBM Enterprise Advanced Economy Tape Cartridge?

Compaction considerations

Compacting data may increase effective storage capacity. The 3490E subsystem uses the improved data recording capability (IDRC) as the default mode. IDRC is a standard feature on the 3490 subsystems. The 3590 and 3592 subsystems use an improved compaction algorithm to increase effective cartridge data capacity.

Recording technology considerations

The 3490 subsystem writes data in the 18-track format. Data written in the 18-track format can be retrieved or read by the 3490E. All 3490E subsystems write data in the 36-track format, which doubles the storage capacity of a tape cartridge.

The 3590 Model B tape drives write data in the 128-track format, the 3590 Model E tape systems write data in the 256-track format, and the 3590 Model H tape systems write data in the 384-track format. Data that is written on a 3590 Model B tape system can also be read on 3590 Model E or Model H tape systems. Data that is written on a 3590 Model E can also be read on a 3590 Model H.

The 3592 Model J tape drives read and write only in EFMT1 format.

The 3592 Model E05 tape drives read and write in EFMT1 and EFMT2 formats.

The encryption-capable 3592 Model E05 tape drives read and write in EFMT1, EFMT2, and EEFMT2 formats.

The 3592 Model E06 tape drives read EFMT1, EFMT2, EEFMT2, EFMT3, and EEFMT3 and write EFMT2, EEFMT2, EFMT3, and EEFMT3 formats.

The 3592 Model E07 tape drives read EFMT1, EFMT2, EEFMT2, EFMT3, EEFMT3, EFMT4, and EEFMT4 and write EFMT3, EEFMT3, EFMT4, and EEFMT4 formats. Write support for EFMT3 and EEFMT3 is provided only on MEDIA9 and MEDIA10 and support for EFMT4 and EEFMT4 is provided with MEDIA9, MEDIA10, MEDIA11, MEDIA12, and MEDIA13. Only read support is provided for media types MEDIA5 through MEDIA8 and EFMT2/EEFMT2 with MEDIA9 and MEDIA10.

Tape capacity considerations

It is important to keep in mind the capacities of the tape cartridges you are using within the tape library to allow the most efficient use of the storage space available. Table 1 depicts the capacity differences between the tape cartridge types.