9710 (StorageTek) Addendum for NonStop Servers

Addendum to the StorageTek™ 9710 for the Tandem Environment
The 5155/5159 Digital Linear Tape CRE and NonStop Kernel
9-49
9.5.3.2 Using COUP to Change Compression Mode
Compression is a COUP device attribute for the 5155, 5159,
5150 or 5151 tape subsystem. If COUP is used to add a 5155,
5159, 5150 or 5151 tape drive to the system configuration,
compression can be enabled or disabled for the tape drive by
specifying the COMPRESSION or NOCOMPRESSION
attribute before adding the device to the system.
To change the compression mode of a tape drive using COUP,
the drive must be stopped. Use the COUP ALTER command
to change the drive attributes, and then restart the drive using
the COUP START command. Only members of the super-
group (user ID 255,n) to use the COUP START, STOP, and
ALTER commands.
Note: The system-wide default compression specification set
in MEDIACOM takes priority over the COUP compression
attribute.
Use the following procedure to change the compression mode
of a 5155, 5159, 5150 or 5151 tape drive using COUP:
1. Stop all processes using the tape drive, and bring down the
tape drive using the PUP DOWN command. (See “Bringing
Down a Cartridge Tape Drive”.)
2. Use COUP commands to determine the current compression
attribute, stop the drive, alter the compression attribute, and
restart the drive. The following example enables
compression for a 5155, 5159, 5150 or 5151 tape drive
named $TAPE1. (Entries shown in boldface show
compression status before and after the ALTER command
was issued.)