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 LPs are running on different CPCs. CF LPs running on the same CPC share the same coupling facility control code EC level. A single CPC cannot support multiple coupling facility levels.
CPC Support for Coupling Facility Code Levels
Coupling Facility Code Planning Considerations for CFLEVEL Migrations
When migrating cf levels, lock, list and cache structure sizes might need to be increased to support new function. for example, when you upgrade from CFCC level 19 to 20 the required size of the structure might increase.
This adjustment can have an impact when the system allocates structures or copies structures from one coupling facility to another at different cf levels.
The coupling facility structure sizer tool can size structures for you and takes into account the amount of space needed for the current cfcc levels.
(Access the tool at: http://www.ibm.com/servers/eserver/zseries/cfsizer/)
The following table summarizes CPC support for the different coupling facility code levels.
|CPC Levels||Level 20||Level 19||Level 18||Level 17||Level 16||Level 15||Level 14|
1. The EC number refers to the SE D partition EC number.
2. All MCLs cited in the table are current as of the publication date of this edition and can be superseded by later MCLs. For the latest EC and MCL information, use IBM Service Link to view the appropriate PSP bucket subset ID for hardware and software maintenance information.
3.Table updated April, 2015
For a list of the software levels that exploit the new function and levels that can coexist with each CF level, please see the Summary of CFLEVEL Functions in the latest copy of the "PR/SM Planning Guide" on IBM ResourceLink, and the "z/OS MVS Setting Up a Sysplex" reference guide available here.
Level 20 Coupling Facility
A level 20 coupling facility (CFLEVEL=20) provides the following enhancements:
Support for Coupling Facility use of Large Memory to improve availability for larger CF cache structures and data sharing performance with larger DB2 Group Buffer Pools (GBP). This support removes inhibitors to using large CF cache structures, enabling use of Large Memory to appropriately scale to larger DB2 Local Buffer Pools (LBP) and Group Buffer Pools (GBP) in data sharing environments.
To learn more about the performance benefits of large DB2 structures, reference IBM zEnterprise System: Performance Report on Exploiting Large Memory for DB2 Buffer Pools with SAP at
Level 19 Coupling Facility
A level 19 coupling facility (CFLEVEL=19) provides the following enhancements:
Support for Coupling Thin Interrupts for improved performance in environments which are sharing Coupling Facility engines. Further support is planned.
Exploitation of the Flash Express feature to help improve WebSphere MQ resiliency by providing a cost-effective way to handle WebSphere MQ shared queue overflows.
Level 18 Coupling Facility
A level 18 coupling facility (CFLEVEL=18) provides the following enhancements:
Serviceability enhancements with more triggers for non-disruptive dumps, additional structure control information in the CF dumps, and enhanced CFCC tracing support
Performance enhancements for dynamic structure size alters and DB2 GBP management
Level 17 Coupling Facility
A level 17 coupling facility (CFLEVEL=17) provides the following enhancements:
Level 16 Coupling Facility
A level 16 coupling facility (CFLEVEL=16) provides the following enhancements:
Level 15 Coupling Facility
A level 15 coupling facility (CFLEVEL=15) provides the following enhancements:
Note: When migrating CF levels, lock, list, and cache structure sizes may need to be increased to support the new function. This adjustment can impact the system when it allocates structures or copies structures from one coupling facility to another at different CF levels. The coupling facility structure sizer tool is designed to size structures for you, and takes into account the amount of space needed for the current CFCC levels.
Level 14 Coupling Facility
A level 14 coupling facility (CFLEVEL=14) provides the following enhancements:
Our testing showed an insignificant increase in structure sizes with a CF LEVEL 14 migration
Level 13 Coupling Facility
A level 13 coupling facility (CFLEVEL=13) provides the following enhancements:
Level 12 Coupling Facility
A level 12 coupling facility (CFLEVEL=12) provides the following enhancements:
Level 11 Coupling Facility
A level 11 coupling facility (CFLEVEL=11) provides the following enhancements:
Level 10 Coupling Facility
A level 10 coupling facility (CFLEVEL=10) provides the following enhancements:
Level 9 Coupling Facility
A level 9 coupling facility (CFLEVEL=9) provides the following enhancements:
Level 8 Coupling Facility
A level 8 coupling facility provides the following enhancements:
Level 7 Coupling Facility
A level 7 coupling facility provides the following enhancements:
Level 6 Coupling Facility
A level 6 coupling facility provides the following enhancements:
Level 5 Coupling Facility
A level 5 coupling facility provides the following enhancements.
Level 4 Coupling Facility
A level 4 coupling facility (CFLEVEL=4) provides dynamic coupling facility dispatching. Additionally, a level 4 coupling facility provides the following enhancements:
Level 3 Coupling Facility
A level 3 coupling facility (CFLEVEL=3) provides list monitoring enhancements accessible through XES. New IXLLIST parameters provide the ability to monitor the use of keyed list structures at a finer level of granularity than previously available in the base list monitoring support. Additionally, with LIC updates, a level 3 coupling facility supports S/390 high performance coupling facility channels (HiPerLinks).
Level 2 Coupling Facility
A level 2 coupling facility (CFLEVEL=2) provides new cache and lock structure functions:
Cache structure enhancements
A cache structure user can now:
Lock structure enhancements
Level 1 Coupling Facility
A level 1 coupling facility (CFLEVEL=1) provides the following enhancements:
Dynamic reconfiguration of coupling facility structures
Dynamic reconfiguration of coupling facility structures, also called structure alteration, provides improved availability by allowing allocated cache, list, and lock structures in a coupling facility LP to:
A structure can expand up to the maximum storage size you specify based on structure usage and coupling facility storage availability. Use the SIZE keyword in the coupling facility resource management policy (CFRM) to specify maximum structure size. Additionally, you can optionally specify an initial structure size (new INITSIZE keyword) that is smaller than the maximum structure size.
List processing enhancements
Beginning with MVS/ESA SP 5.2, the XES IXLLIST service offers additional support for list structure processing in a level 1 coupling facility. New IXLLIST parameters provide these new functions. For more information, see the Sysplex Services Guide, GC28-1495.