z/OS Release 8 CPU SMF Record Changes

(Originally posted 2006-12-13.)

I’ve just been looking at some fascinating SMF 70 records. They come from a System z9 EC S54 machine and the LPAR they’re from is running z/OS Release 8. I say “fascinating” because:

  • I’ve not seen an S54’s data before. (This is the largest z9 machine – with all 4 processor books fully populated with engines.)
  • There are changes that I asked RMF (and PR/SM) Development to add into Release 8 that I’m delighted to see in the data. (It’s nice when a developer says “sure thing, Martin, it’ll be in Release 8” but it’s even nicer when you get to see Production SMF data with the changes in.)

Some of the changes described below are not, in fairness, at my behest.

Engine Counts

The final section of the SMF 70 record used to simply be a lookup table for “pool number” versus “characterised processor type name”. So, for example zAAPs would be in Pool 3 – for z9. (For z990 they’re in Pool 2, alongside all the rest of the non-GCP processor types. But modern machines often have enough logical processors (and LPARs) to cause some of the Logical Processor sections in the record to overflow to second (and perhaps third) records. This means working out the configuration of a machine from SMF 70 requires you to process several records as one. Certainly our code (and probably that of other programs) doesn’t process them as one. So in Release 8 there’s a very useful enhancement…

Each of the “lookup table” sections now has a count of the number of each engine type. So, for example, the ICF lookup table section has the number of ICF processors on the physical machine.

Hardware Model

I asked for this a while back and I thought I had it in z/OS Release 7. However I’ve seen a number of sets of R.7 where this field isn’t in the record. But in this case the field is populated with “S54”. I assume this has little to do with z/OS Release 8 vs Release 7, but rather more to do with microcode levels on the processor. And the importance of this is that I can be sensitive to the number of books installed on the machine when recommending things like upgrades.

Machine Serial Number

This, which I asked for, has two purposes:

  • I can look up the Vital Product Data (VPD) for the machine in one of our internal databases. (Customer Engineers have access to a nice tool from Montpellier called VPDFWIN, which formats VPD into a useful display.) Amongst many other things it tells me the book count (see above), the number and size of memory cards on each book, and the I/O subsystem features on the machine. So, again, I would hope to do a better consulting job.
  • I can correlate the SMF 70 view of CPU with the SMF 74 Subtype 4 view of CPU. (SMF 74 Subtype 4 gives you a wealth of very useful information about Coupling Facilities.) So, for instance, I can tell which machine a CF is on. So I don’t have to ask you the stupid question. 🙂

    Now, I only have SMF 89 and 70 for this machine so far, so I can’t also test if the machine serial number has shown up in the 74-4 record as well. I’m sure it has – as I asked for it at the same time as for it to be in the SMF 70 record.

I concede these are small “fit and finish” items but they do make the SMF 70 data just that little bit more useful and usable.

Published by Martin Packer

I'm a mainframe performance guy and have been for the past 35 years. But I play with lots of other technologies as well.

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