z/VSE 6.2 Preview: zHPF support - next blog entry on May 3, 2017
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Today I want to describe another enhancement announced in the z/VSE 6.2 Preview and available in forth quarter 2017 - the High Performance FICON for z Systems (zHPF) support.
The zHPF channel Input/Output (I/O) architecture can improve the execution of small block I/O requests. z/VSE will translate applicable I/O commands into the zHPF protocol and thus transparently exploit the zHPF protocol for user applications. No adaptation is required. Multiple channels commands are sent as a single entity to the control unit. That is the channel forwards a chain of commands and has no longer to keep track of each single CCW (Channel Command Word). This may lead to reduced overhead and increases the I/O rate on a channel. The performance benefits depend on your workload. zHPF support is provided for ECKD channel commands.
The SYSDEF SYSTEM command is extended by a new zHPF parameter. After IPL completed you can start the zHPF support via SYSDEF SYSTEM,ZHPF=START. You may stop the zHPF support via SYSDEF SYSTEM,ZHPF=STOP, and restart it any time. So you can easily verify, if your workload can benefit from z/VSE's zHPF support. I/O timings can be verified via the SIR SMF command.
We have a long weekend, because May 1 is a public holiday in Germany. Therefore I plan my next blog entry for Wednesday - May 3.
Have a good weekend.