If you are a project manager leading a mainframe project, I’d like to share with you some general action items to include in your project plan. My first suggestion is that you request from your mainframe vendor a current list of the features on your mainframe today and review the list together. This report is sometimes called a detail report.
This report will show you the machine type you have, the model, the capacity setting, the capacity marker, the amount of memory, and how many and what types of adapter cards are installed.
It’s a good starting place to see where you are today.
You can learn some helpful things from this report – things that might prompt follow-on questions and potentially save you some money.
For example, you might see that you have many more ESCON adapters than you need today. At one time, ESCON was leading edge technology, replacing the slow, bulky parallel channels. But ESCON is now old (and fading) technology and many mainframe users have lots of unused ESCON ports because they have either eliminated older ESCON-attached I/O devices or migrated from ESCON to the far superior FICON technology.
So, for example, you might discover that you have 48 ESCON ports, but you’re only using 12 of them.
When your vendor proposes a new mainframe, they may initially assume that you still need all 48 ESCON ports. The number of ports you need drives the number of cards you get. ESCON ports are “enabled” in groups of four ports. The cards themselves have sixteen ports, of which one is a spare. And, the System z will always have at least two cards for the sake of redundancy and availability.
Let’s explore this a bit. If I have 48 ESCON ports available for use, then I’ll have four 16-port ESCON cards. Why not three cards instead of four? After all 3 x 16=48. Because one port on each card is reserved as a spare. So, three cards give me 45 available ports. To get 48 ports, then, I need four cards.
Four cards actually give you 60 ports (ignoring spares), but ports are “enabled” (think $$$) in groups of four. Doing that gives you better granularity, so you don’t have to buy many more ports than you need. So you paid for 48 ports.
If I now only require 12 ESCON ports, then I only need two ESCON cards (remember, that’s the minimum for the sake of redundancy). So I can go from four ESCON cards down to two ESCON cards. That frees up two slots for other uses – OSA or FICON, for example – so, even though I already paid for 48 ESCON, I may save myself some money down the road (or even immediately) by freeing up a couple of slots for use by other cards, thus potentially avoiding having to purchase another I/O cage or drawer.
As you go through your detail report, you may see other things you can eliminate: older OSA technology (e.g., Fast Ethernet), etc.
One word of caution: In the case of ESCON, be sure that you get accurate data as to what’s being used and what isn’t. You don’t want to scale back and then discover that you actually need more than you thought. Check the adapters to see if a cable is plugged in. If there is a cable, but you think it’s not connected to anything on the other end, you can always unplug it (within your change management guidelines) to verify that it’s no longer in use.
But my primary suggestion is simply to get the detail report and look it over. If it prompts questions, ask them. If there’s something on the current machine that’s missing from the newly proposed machine, ask why. Check the features and check the quantities on everything, just to be sure.
