Running z/VSE With a Linux Fast Path

This section describes the Fast Path to Linux on z Systems function, referred to simply as Linux Fast Path (or LFP).

Linux Fast Path allows selected TCP/IP applications to communicate with the TCP/IP stack on Linux on z Systems (IBM Z) without using a TCP/IP stack on z/VSE.

The Linux Fast Path can be run in a z/VM-to-z/VM, an LPAR-to-LPAR or a z/VM-to-LPAR environment.
  • If you run LFP in a z/VM-to-z/VM environment, both z/VSE and Linux on z Systems (IBM Z) run in the same z/VM-mode LPAR. An IUCV connection is used between z/VSE and Linux on z Systems (IBM Z). If you do not prefer to run a Linux on z Systems system on your own, the z/VSE - z/VM IP Assist feature described in z/VSE - z/VM IP Assist might be an alternative.
  • If you run LFP in an LPAR-to-LPAR environment, both z/VSE and Linux on z Systems (IBM Z) run in their own LPARs. A HiperSockets connection is used between z/VSE and Linux on z Systems (IBM Z).
  • If you run Linux Fast Path (LFP) in an z/VM-to-LPAR environment, z/VSE runs as z/VM guest and Linux on z Systems runs in its own LPAR. A HiperSockets connection is used between z/VSE and Linux on z Systems. This requires z/VM Version 6 Release 3 or later, to enable 'HiperSockets Completion Queue' functionality for z/VM guests.

For a general introduction to Fast Path to Linux on z Systems refer to Planning.

If using socket applications written in LE/C with LFP, you must configure the LE/C TCP/IP Socket API Multiplexer. Refer to Selecting the TCP/IP and SSL Implementation to use for information about how to select the TCP/IP and SSL implementation to use with your application using the LE/C Socket API Multiplexer.

This section contains these main topics: