Short Description: With the option turned on, data written to the transaction log will be compressed using the zSeries CMPSC instruction instead of Domino software.
The following was taken from the Domino 7 Release Notes:
Domino 7 on the zSeries platforms (z/OS and Linux) can optionally exploit hardware-assisted data compression for transaction logging. With the option turned on, data written to the transaction log will be compressed using the zSeries CMPSC instruction instead of Domino software. If data is then accessed from the transaction log the Domino 7 zSeries server will use the appropriate technique (CMPSC instruction or Domino software) to decompress. Data in transaction logs that has been compressed using zSeries hardware-assisted data compression cannot be used on non-zSeries Domino platforms or pre-Domino 7 zSeries servers.
By default, hardware-assisted data compression for transaction logging is enabled. The feature can be disabled by starting the Domino server with "TRANSLOG_HardwareCompress=0" set in notes.ini.
The CMPSC instruction requires less CPU cycles than Domino software to do the compression. Depending on the server workload, using the hardware-assisted data compression for the transaction logging feature can result in a CPU utilization improvement.
The Domino software to compress the transaction logs uses a more comprehensive technique to do the compression than the CMPSC instruction. Therefore, the storage required for transaction logs may be greater when the hardware-assisted data compression for the transaction logging feature is enabled.
There is no kown UI setting for this notes.ini variable. But you can specify this setting in the notes.ini settings tab of the configuration settings document.
IBM Technote 1219163