A customer is running Coupling Facility Control Code (CFCC) Level 20 on a z13, and is upgrading to a z14 at CFCC Level 22. What risk does this introduce to the sysplex?

Question

Options

• ACFSizer may cause structures to be rebuilt.
• BList, lock, and cache structures may require additional memory.
• CCoupling Facility Resource Management policy could run out of storage.
• DEach system connecting to the sysplex must be upgraded to the same CFCC Level.

• A
  2% (1)
• B
  81% (39)
• C
  13% (6)
• D
  4% (2)

Explanation

Upgrading to CFCC Level 22 introduces enhancements to how list, lock, and cache structures are formatted internally - the new level adds control information and structural overhead that wasn't present at Level 20, meaning existing CF structures rebuilt at the new level will consume more storage than before, potentially exhausting allocated space if they weren't sized with this growth in mind.

Why the distractors are wrong:

• A is wrong because CFSizer is a capacity planning tool - it models and recommends sizes but does not trigger structure rebuilds itself.
• C is wrong because CFRM (Coupling Facility Resource Management) policy governs structure allocation priorities and placement, not a component that "runs out of storage" as a direct result of a CFCC level change.
• D is wrong because IBM's sysplex architecture explicitly supports mixed CFCC levels; there is no requirement that all connected systems must match the CF's CFCC level.

Memory tip: Think of CFCC levels like a document format version - opening an old file in a newer app may reformat it with richer metadata, making it larger. Similarly, higher CFCC levels reformat structures with more overhead, so "higher level = higher storage cost." When planning a CFCC upgrade, always re-run CFSizer against the new level to revalidate structure sizes.

No community discussion yet for this question.