Cfcc Level 21 - IBM z13s Technical Manual

Consideration: Because coupling link connectivity to System z10 and previous systems is
not supported, introduction of z13s into existing installations might require more planning.
Also, consider the level of CFCC. For more information, see "Coupling link considerations"
on page 181.

7.8.1 CFCC Level 21

CFCC level 21 is delivered on the z13s with driver level 27. CFCC Level 21 introduces the
following enhancements:
Usability enhancement:
– Enable systems management applications to collect valid coupling facility (CF) LPAR
information by using z/OS BCPii.
• System type (CFCC), System Level (CFCC level).
• Dynamic dispatch settings to indicate CF state (dedicated, shared, thin interrupt).
Availability enhancement:
– Asynchronous CF duplexing for lock structures. Secondary structure updates are
performed asynchronously with respect to primary updates
• Designed to drive out cross-site latencies that exist today when replicating CF data
• Designed to avoid the need for synchronous speed-of-light communication delays
• Improves performance with cross-site duplexing of lock structures at distance
• Maintains robust failure recovery capability through the redundancy of duplexing
• Reduces z/OS, CF, and link utilization overhead costs associated with synchronous
– Requires CFCC level 21 and service level 02.16 and z/OS V2.2 SPE with PTFs for
APAR OA47796.
Large memory support:
– Improve availability/scalability for larger CF cache structures and data sharing
performance with larger DB2 group buffer pools (GBPs).
– This support removes inhibitors to using large CF structures, enabling use of Large
Memory to scale to larger DB2 local buffer pools (LBPs) and GBPs in data sharing
environments.
– CF structure size remains at a maximum of 1 TB.
Support for the new IBM ICA for short distance coupling.
z13s systems with CFCC Level 21 require z/OS V1R12 or later, and z/VM V6R2 or later for
guest virtual coupling.
across distance
during the processing of every duplexed update operation
duplexing of lock structures
Chapter 7. Software support
293