Re: VM/370 Hercules Optimisation
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Bob, ? You have just given me nightmares!? Did you have the SAS ¡°C¡± compiler as well! Mind you we had Oracle as well but thankfully no MVS¡ .. but it could be worse VM was great compared to VAX/VMS on an X25 network. Those paged like mad. User types a character, page in the users DCL shell, shell decides its an ¡°A¡± and needs to echo it. Queues an IO to echo it, gets paged out¡. ? One of my mates worked at a bank. He really preferred All-in-one to PROFS but said there was no way he could afford enough VAX hardware to roll it out to the folks he wanted to have it¡ Happy Days¡ simpler times¡. ? Dave ?
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From: [email protected] <[email protected]> On Behalf Of Bob Polmanter
Sent: 30 January 2020 23:44
To: [email protected]
Subject: Re: [h390-vm] VM/370 Hercules Optimisation? >I said ¡°can fall of¡±! Of course in our situation , running 360 and 370 operating systems with typically a trivial workload on >hardware that out performs anything that the original software ever ran on by a factor of around 10 its unlikely that we will >experience the sort of problems small sites experienced on 4330, 4340 and 4360 mid-range boxes.
Dave, I understand.
System performance became something of a career thing for me back in the day.? We did run MVS as a guest under VM/SP HPO in a production environment on a 16MB 4381, and as the system programmer I had to make it work and make it run well, or else.? We ran MVS in an 8 MB V=R space, using PMA? (Preferred Machine Assist, remember that?).? The CMS users got the other 8 MB.? We had a couple of hundred CMS users in the directory but most of the time we would have 40-60 logged on at most, and probably a lot of them were idle.? MVS always had a large batch load active, but hardly any TSO activity fortunately (for the system).
The bane of my existence was a statistical product called SAS, which for us ran under CMS.? The mathematicians and programming staff at my site loved it, but it was nothing but a headache for me.? The thing was a pig, a pile of bloated compiled code and it sent our paging rate skyrocketing.? After a few years the SAS people did get a large portion of their product into shared segments and that helped tremendously.? But it was a CPU hog even still.
Later still, we eventually got 32MB on the 4381 and that helped a lot.?? All good stuff.
Regards,
Bob
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