A security administrator would like to know more details about Coupling Facility Encryption. Their main concern is with Coupling Facility CPU overhead once encryption has been implemented. Which ICF…

Question

Options

• AOverhead is dependent on the number and type of structures to be encrypted.
• BEncryption is z/OS based and will not impact Coupling Facility overhead.
• CA Pervasive Encryption assessment can determine the overhead.
• DOnce ICA links are implemented, overhead will not be impacted.

• A
  81% (21)
• B
  4% (1)
• C
  12% (3)
• D
  4% (1)

Explanation

Option A is correct because Coupling Facility (CF) Encryption operates directly within the CF itself - when structures are encrypted, the ICF must perform cryptographic operations on each access, and the total overhead scales with how many structures are encrypted and what types they are (cache, list, lock structures differ in access patterns and size).

Why the distractors are wrong:

• B is incorrect because CF Encryption is not purely z/OS-based - the encryption/decryption work happens inside the Coupling Facility, so ICF CPU overhead is a real and direct consequence.
• C is a red herring; Pervasive Encryption is a broader IBM framework for encrypting data at rest and in flight across the enterprise, but it does not specifically quantify ICF structure-level overhead.
• D is incorrect because ICA (Internal Coupling Adapter) links pertain to connectivity bandwidth and latency between the CF and LPARs - switching link types does not eliminate the CPU cost of encrypting/decrypting structure data.

Memory tip: Think "structure count and type drive the overhead" - just as encrypting more and larger files costs more CPU on a server, encrypting more (and busier) CF structures drives up ICF CPU usage proportionally. If you remember that the overhead is structural, you'll naturally land on A.

No community discussion yet for this question.