Tape drive normally come with hardware compression feature. For example an LTO3 tape can store 400GB data with the hardware compression feature disabled, and able to store 800GB data with hardware compression feature enabled. Hardware compression is done at the tape drive, instead of using TAR or ZIP command.
By default, the hardware compression is enabled. To disable it, you can issue command below:
mt -f /dev/st0 compress 0
To enable back the compression feature:
mt -f /dev/st0 compress 1
To disable the default option of hardware compression:
mt -f /dev/st0 defcompression -1
To enable back the default option:
mt -f /dev/st0 defcompression 1
Transfer rate is much higher with hardware compression enabled.