How do you determine the number of Crypto Express cards that you need and/or when to consider purchasing more cards? Unfortunately, there isn't an easy way to determine the number of cards needed up front. Hopefully the information below will help.
Initial Card Setup
You would generally start with at least 2 cards of each type needed in your environment (e.g. CCA Accelerator, CCA Coprocessor, EP11 Coprocessor) for redundancy. If one card needs to be taken offline (for example, MCL upgrade), the second card (loaded with the same MK as the first) would be able to handle the same requests.
Ongoing Card Management
After initial setup (with a minimum of 2 cards), the number of additional crypto cards needed is typically based on what you consider to be an acceptable threshold for utilization per card. You would run in an environment with a baseline number of cards and monitor their usage.
Monitoring Card Usage
Two options for viewing and/or monitoring card usage are z/OS RMF and the Monitors Dashboard on the SE:
- z/OS RMF can create post-processed Crypto Hardware Activity reports which would show the utilization percentage for each card. https://www.ibm.com/support/knowledgecenter/SSLTBW_2.1.0/com.ibm.zos.v2r1.erbb500/erbb500402.htm
- The Monitors Dashboard on the SE can be used in real time to view adapter type and monitor usage. It takes measurements every 15 seconds and displays the value. You can also start a histogram to show adapter utilization as a line graph over time. https://www.ibm.com/support/knowledgecenter/HW11P_2.13.1/com.ibm.hwmca.kc_se.doc/dashboard/Dashboard.html
So, the step-by-step process would be:
- Establish a crypto card utilization threshold (for example, 50% utilization)
- Monitor crypto card utilization over a period of time
- If the crypto card utilization exceeds the threshold, decide if you want to purchase more cards
Crypto Card Performance / Throughput
For general crypto card performance throughput, reference the Crypto Performance WhitePaper associated with your z System / Crypto Express cards