162 IBM ^ zSeries 990 Technical Guide
7.2.2 Coupling Facility and CFCC considerations
The z990 can participate in a Parallel Sysplex when the Coupling Facility resides in a G5 or
G6 or any zSeries Server. When system images in the sysplex reside across z990 and
non-z990 Servers, consideration must be given for compatibility support; see 6.2.1,
“Compatibility Support for z/OS” on page 134. When any system image in a Parallel Sysplex
resides on a z990 server, all other system images and Coupling Facilities must be on 9672
G5 or G6 or zSeries hardware.
The location of the Coupling Facility and the level of the Coupling Facility Control Code
(CFCC) must also be considered. See Table 7-1 for Coupling Facility Control Code
requirements when the Coupling Facility resides on a non-z990 server and is connected to a
z/OS image on a z990, or when CF duplexing is used and one Coupling Facility resides on
the z990 server.
Table 7-1 z990 CF code level considerations
The initial support of the CFCC on the z990 Server is level 12. Typically each new level of
CFCC introduces additional functionality. Coupling Facilities within a Parallel Sysplex should
be at equivalent levels, and the precise CFCC level supported can depend on server type.
CFFC level 13 is current as of May 28, 2004. CFCC level 13 introduces some availability and
performance enhancements.
To support migration from one Coupling Facility level to the next, you can run different levels
of the Coupling Facility concurrently as long as the Coupling Facility logical partitions are
running on different servers.
CF logical partitions running on the same server share the same Coupling Facility Control
Code EC level. A single server cannot support multiple Coupling Facility levels. Table 7-2 on
page 163 summarizes the CFCC CFLEVELs supported on the z990 servers.
7.2.3 CFCC enhanced patch apply
Patch application to CFCC level 13 code is designed to eliminate the need for a Power-on
Reset of the z990 when a ‘disruptive’ patch must be applied.
This method of patch application enables you to:
򐂰 Apply the patch on one of the available Coupling Facilities. A good place would be the test
Coupling Facility of a test sysplex if one is available. If the test of the CFCC code is
successful, it can be applied to production Coupling Facility on the same z990. To use the
updated CFCC code to a CF logical partition, simply deactivate and reactivate the
CF with connections to z990
z/OS image or z990 (CF
Connected to a z990 with 15
or less LPARs defined
Connected to a z990 with
more than 15 LPARs defined
Pre-G5 CPC Not supported Not supported
G5/G6 CPC CFCC level 11 CFCC level 11
z800 or z900 CPC CFCC level 12
(not recommended
a. It is recommended that the Compatibility patch be installed prior to the z990 installation. Not
installing the patch opens up the possibility that a z990 will have more than 15 partitions defined
later without the Compatibility patch being installed.
b. Installation of the Compatibility patch is disruptive.
CFCC level 12
Compatibility patch
z990 or z890 CPC CFCC level 13 CFCC level 13

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