5190/5194 Modular Tape Subsystem Manual

Operating the Cartridge Tape Drive and ACL
5190/5194 Modular Tape Subsystem Manual—426878-002
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How to Change Labeled-Tape Processing
Configuration
How to Change Labeled-Tape Processing Configuration
With labeled-tape processing enabled, you can use both labeled and unlabeled tapes.
You can override the CONFTEXT entry by using SCF to alter the LABELTAPE
attribute. First stop the drive, then use the SCF ALTER command; for example:
->ALTER TAPE $TAPE0, LABELTAPE ON
Where to Get More Information About Labeled-Tape Processing
The following table tells you where to get more information on labeled tapes, labeled-
tape processing, tape operator tasks, and utilities for managing tape operations:
Controlling Data Compression (5190 Tape
Drive)
Improved Data Recording Capability (IDRC) data compression is a standard feature on
the 5190 and 5194 tape drives. The 5190 drive writes uncompressed data (unless
compression mode is on). The 5194 tape drive always has data compression mode
on. When activated for the 5190 drive, compression allows the drive to store two or
more times as much data on a cartridge tape. However, the amount of compression
varies with the data being written. See Table 1-3
on page 1-6.
The system does not detect any difference in writing or reading compressed or
uncompressed data. A disk file of 200 kilobytes written to tape in compressed mode is
still a 200-kilobyte file on the tape, but it consumes less tape than the same file written
with uncompressed data.
The Compression LED
The COMP (compression) LED on the tape drive or ACL front panel indicates when the
drive is processing compressed data. The COMP LED lights when the drive writes
compressed data to tape or when the drive reads compressed data to the tape drive
buffer.
For more information about... Read...
Managing labeled-tape processing Guardian User’s Guide
BACKUP utility, RESTORE utility,
and TAPECOM utility
Guardian Disk and Tape Utilities Reference Manual
File Utility Program (FUP) File Utility Program (FUP) Reference Manual
MEDIACOM and tape-label formats DSM/Tape Catalog Operator Interface (MEDIACOM)
Manual
Enabling labeled-tape processing SCF Reference Manual for the Storage Subsystem