Hints Of Other Systems
MartinPacker 11000094DH Visits (1947)
You can blame the weather for this post. I’m writing it on a flight above thick cloud on my way to Munich and then to Budapest for this year’s European System z Technical University.
I like to see the complete picture when I’m examining systems: It makes getting it right so much easier. And there’s something rather satisfying about getting your arms all the way round something.
But I don’t always get “complete” data from a customer. So I work with what I can get and this post is about what I can infer about others systems whose data I don’t have.
When I talk of “not getting data from all systems” I should perhaps clarify: Most installations run RMF on most of their systems and the SMFID in the header of SMF records is the system RMF ran on. I do get information at some level about other systems from RMF SMF records, but its far from complete.
There are a number of good reasons why customers don’t send me data for all systems, including:
The last of these is the most common, particularly with installations jamming all their Production systems into one Sysplex.
For some situations I really do need to see all systems. A few examples that come to mind are:
But generally I can tolerate seeing data from a subset, so I’m not insistent when I don’t need to be.
The question of the day is “how much can I glean about systems whose data isn’t present?” Because maybe I can get a good understanding of an installation anyway. So let’s see what we can do.
Spotting Other LPARs
You can see all the LPARs on a physical machine from SMF 70 Subtype 1 Logical Partition Data Section. You get further detail on logical engines, memory allocated and CPU Utilisation in the 70–1 Logical Processor Data Section for these LPARs.
Among other things the names and definitions of these LPARs can be fascinating.
You also get a small amount of data for deactivated LPARs, most particularly the name and Partition Number. It’s relevant to know for example that one machine has an activated SYSB and another has a deactivated one.
Spotting Other Systems
I can sometimes see the existence of other systems, not on the same footprint, Here are a couple of examples of how:
Spotting Coupling Facilities
RMF SMF 74–4 records are cut for all coupling facilities in the Parallel Sysplex, regardless of which footprint they are on.
This data nowadays includes the machine serial number and LPAR Number.
Sometimes I infer the existence of a whole machine - where none of the systems on it provided RMF data - from the existence of a coupling facility on it.
And What Of It?
Maybe not much to you if you work in a customer. But to me this fills in handy gaps. And it’s nice to spot probably unintended clues.
(Completed on a bumpy ride from Munich to Budapest.)