Enabling compression

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7.1 LPAR mode z/VM guest

Control Improved Data Recording Capability (IDRC) compression with the mt command provided by the RPM mt-st.

About this task

Compression is off after the tape device driver is loaded.

Procedure

To enable compression, issue: 
# mt -f <node> compression
or 
# mt -f <node> compression 1
where <node> is the device node for a character device, for example, /dev/ntibm0.
To disable compression, issue: 
# mt -f <tape> compression 0

Any other numeric value has no effect, and any other argument disables compression.

Example

To enable compression for a tape device with a device node /dev/ntibm0 issue: 
# mt -f /dev/ntibm0 compression 1