Archive for the 'zVM' Category

Mainframe Assembler Language 2.0

Those that still follow my blog from my days working in the IBM mainframe arena might be interested in the following.

One of the stalwarts of software at IBM, and self described grand poobar of High Level Assembler, John R. Ehrman has a 1300-page 2.0 version of his book “Assembler Language Programming for IBM System z™ Servers ” and it’s available in PDF form here. There are a wealth of other assembler resources that John has contributed here on

VM Master Class

As is the way, the older you get the more entangled your life becomes. My ex-Wife, Wendy Cathcart, nee Foster, died of cancer recently, such a waste, a fantastic, vibrant woman and great Mother to our children. After the funeral the kids were saying how they’d hardly got any video of her. I had on my shelf, unwatched for probably 10-years or more a stack of VCR tapes. I’d meant to do something with them, but never got around to it.

I put the tapes into Expressions in video here in Austin, they were ever so helpful and were able to go from UK PAL format VCR tapes to DVD, to MPEG-4. Two of the tapes contained the summary videos from the 1992 and 1993, IBM VM Master Class conferences. And, here’s were the entanglement comes in. Wendy never much got involved in my work, we went on many business trips together, one of the most memorable was driving from North London to Cannes in the South of France. I had a number of presentations to give, and the first one was after lunch on Monday, the first day. I went to do registration and other related stuff Monday morning. I came back to the room to get the car keys and go and collect my overhead transparencies and handout copies from the car. Unfortunately for me, Wendy had set off in the car with a number of the other wives to go visit Nice, France and my slides and handouts were in the trunk/boot. D’oh.

Unlike this week where my twitter stream has been tweet bombed by #VMWorld, back in the 1980’s there were almost no VM conferences. IBM had held a couple of internal conferences, and the SHARE User group in the USA had a very active virtual machine group, there really wasn’t anything in Europe except 1-day user group meetings. My UK VM User Group, had been inspirational for me and I wanted to give something back and give other virtual machine systems programmers and administrators and chance to get together over an extended period, talk with each other, learn about the latest technologies and hear from some of the masters in the field.

And so it was that I worked through 1990 and 1991 with Paul Maceke to plan, and deliver the first ever VM Master Class. We held it at an IBM Education facility, La Hulpe, which was in a forest outside of Brussels, Belgium. As I recall, we had people met at the airport and bused them in in Sunday and the conference ran through Friday lunchtime, when we bused them back to the airport. Everything was done on site, meals, classes and hotel rooms. Back in the 1970’s and 1980’s in was required for computer systems to be represented by something iconic, for VM it was the bear. You can read why and almost everything else about the history of VM here on Melinda Varians web page, heck you can even get kindle format version of the history.

So, when it came to the Master Class we needed a bear related logo. Thats where Wendy came in. She drew the “graduate bear”, for which Paul got not only included in the folders, but also metal pins, what a star. Come the 1993 VM Master Class, Wendy did the artwork for the VM Bear and it’s Client/Server Cousin sitting on top of the world and as I remember, this time Paul actually got real soft toy bears. Thanks for all the great memories Wendy, the videos on youtube also remind me of many great people from the community, who came you name? Please feel free to add with comments here to avoid the Youtube comment minefield.

I’ll start with Dick Newson, and John Hartman, couldn’t be two different people, both totally innovative, great software developers and designers.

An old man and money

I was just sent a link to this ConnectedPlanet article by Susana Schwartz, and given my background in mainframes and x86 asked what I thought of the central premise. The analogy that came to mind almost immediately was too good not share.

The question the article was addressing was “will the IBM zEnterprise make mainframes sexy again?” My analogy, Hugh Hefner! Do you think Hugh Hefner is sexy? He has all the money, is a great revenue generator has some good products, but mostly while they do the same stuff they’ve always done, are looking a bit long in the tooth. What’s interesting is what surrounds Hugh. Same with zEnterprise, only there are much better ways to get that smart technology.

After a few miss-starts with a google search for “old man and young girls” – that will have set off some alarm bells in Dell IT, I set Google safesearch to strict and search for “old man with young women” and here we have it, my analogy for the IBM zEnterprise.

Image courtesy and copyright of the

Image courtesy and copyright of the

Do you want Hugh Hefner in the middle? He’s worth loads of money…

Any similarity between Hugh Hefner and an IBM mainframe is entirely coincidental, after all we all know mainframes are older and come from New York. Hugh is from Chicago.

Feel free to use the analogy to argue either way… just be careful to keep the discussion work safe. I’ve still got that J3000 spoof press release somewhere as well.

70% of something is better than..

70% of nothing at all. [With apologies to Double Exposure]

As I’ve said before, I’m an avid reader of Robin Bloors Have Mac Will Blog, blog. I also follow him on twitter where he is @robinbloor. Sadly his blog doesn’t accept trackbacks, but I’ll leave a short comment so he gets to see this.

His latest blog entry, CA:Dancing with dinosaurs comes across as a bit of a puff piece in support of Computer Associates.

On the CA involvement with mainframes, Bloor seems to have overlooked the fact that CA has John Swainson as CEO, and Don Ferguson as Chief Architect. John was previously an IBM VP, Don an IBM Fellow and both Don and John were variously in charge of significant IBM Software Group projects/products.

Personally I’d like to see someone from IBM find/quote a source for that 70% data number. It’s been used for years and years with little or no foundation. Jim Porell quoted this number in some of his excellent and more recent System Z strategy presentations, It’s dated from, I think, 1995.

Secondly, I’d guess it depends what you can business critical data these days. If Google collapsed or had their data centers in Silicon Valley interrupted with the loss of Google docs, YouTube, Google search, Maps and similarly Microsoft and/or Yahoo went offline… I’d suspect the whole notion that 70% of business critical data resides of mainframes would be laughable. Yes, a large percentage of purely text based transactional data is on mainframes and yes the value of those transactions exceeds any other platform, but that is far from 70% of anything much these days… Increasingly these days startups, SME’s and Web 2.0 business don’t use mainframes for even their text based transactional data.

Finally on the Bloor/CA assertion that installing mainframe software is arcane. That maybe, but here I’m still in full agreement of the mainframe folks, especially if you are talking about real mainframe software as IBM would have it, installed by SMP/E. One of my few claims to fame was reverse engineering key parts of the IBM Mainframe VM service process nearly 20-years now. It was then, and SMP/E is now, still is years ahead of anything in the Windows and UNIX space for pre-req, co-req, if-req processing; the ability to build and maintain multiple non-trivial systems from a single data store using binary only program objects. CA are not the first to spot the need to provide an interface other than ISPF and JCL to build these jobs streams.

But really, continuing to label mainframes as dinosaurs is so 1990’s, it’s like describing Lance Armstrong as a push bike rider.

Simon Perry, Principal Associate Analyst – Sustainability, Quocirca, has written a similar piece with a little more detail entitled Mainframe management gets its swagger.

IBM Big Box quandary

In another follow-up from EMC World, the last session I went to was “EMC System z, z/OS, z/Linux and z/VM”. I thought it might be useful to hear what people were doing in the mainframe space, although largely unrelated to my current job. It was almost 10-years to the day that I was at IBM, were writing the z/Linux strategy, hearing about early successes etc. and strangely, current EMC CTO Jeff Nick and I were engaged in vigourous debate about implementation details of z/Linux the night before we went and told SAP about IBM’s plans.

The EMC World session demonstrated, that as much as things change, the they stay the same. It also reminded me, how borked the IT industry is, that we mostly force customers to choose by pricing rather than function. 10-12 years ago z/Linux on the mainframe was all about giving customers new function, a new way to exploit the technology that they’d already invested in. It was of course also to further establish the mainframes role as a server consolidation platform through virtualization and high levels of utilization.(1)

What I heard were two conflicting and confusing stories, at least they should be for IBM. The first was a customer who was moving all his Oracle workloads from a large IBM Power Systems server to z/Linux on the mainframe. Why? Becuase the licensing on the IBM Power server was too expensive. Using z/Linux, and the Integrated Facility for Linux (IFL) allows organizations to do a cost avoidance exercise. Processor capacity on the IFL doesn’t count towards the total installed, general processor capacity and hence doesn’t bump up the overall software licensing costs for all the other users. It’s a complex discussion and that wasn’t the purpose of this post, so I’ll leave it at that.

This might be considered a win for IBM, but actually it was a loss. It’s also a loss for the customer. IBM lost because the processing was being moved from it’s growth platform, IBM Power Systems, to the legacy System z. It’s good for z since it consolidates it’s hold in that organization, or probably does. Once the customer has done the migration and conversion, it will be interesting to see how they feel the performance compares. IBM often refers to IFL and it’s close relatives the ziip and zaap as speciality engines. Giving the impression that they perform faster than the normal System z processors. It’s largely an urban myth though, since these “specialty” engines really only deliver the same performance, they are just measured, monitored and priced differently.

The customer lost becuase they’ve spent time and effort to move from one architecture to another, really only to avoid software and server pricing issues. While the System z folks will argue the benefits of their platform, and I’m not about to “dis” them, actually the IBM Power server can pretty mouch deliver a good enough implementation as to make the difference, largely irrelavant.

The second confliction I heard about was from EMC themselves. The second main topic of the session was a discussion about moving some of the EMC Symmetrix products off the mainframe, as customers have reported that they are using too much mainframe capacity to run. The guys from EMC were thinking of moving the function of the products to commodity x86 processors and then linking those via high speed networking into the mainframe. This would move the function out of band and save mainframe processor cycles, which in turn would avoid an upgrade, which in turn would avoid bumping the software costs up for all users.

I was surprised how quickly I interjected and started talking about WLM SRM Enclaves and moving the EMC apps to run on z/Linux etc. This surely makes much more sense.

I was left with though a definate impression that there are still hard times ahead for IBM in large non-X86 virtualized servers. Not that they are not great pieces of engineering, they are. But getting to grips with software pricing once and for all should really be their prime focus, not a secondary or tertiary one. We were working towards pay per use once before, time to revist me thinks.

(1) Sport the irony of this statement given the preceeding “Nano, Nano” post!

Virtualization, The Recession and The Mainframe

Robin Bloor has posted an interesting entry on his “Have mac will blog” blog on the above subject. He got a few small things wrong, well mostly, he got all the facts wrong but, right from a populist historical rewrite perspective. Of course I posted a comment, but as always made a few typos that I now cannot correct, so here is the corrected version(feel free to delete the original comments Robin… or just make fun of me for the mistakes, but know I was typing outdoors at the South Austin Trailer Park and Eatery, with open toe sandles on and it’s cold tonight in Austin, geeky I know!)

What do they say about a person who is always looking back to their successes? Well, in my case, it’s only becuase I can’t post on my future successes, they are considered too confidential for me to even leave slides with customers when I visit… 

VM revisited, enjoy:


Mark Cathcart (Should have) said,
on October 23rd, 2008 at 8:16 pm

Actually Robin, while it’s true that the S/360 operating systems were written in Assembler, and much of the 370 operating systems, PL/S was already in use for some of the large and complex components.

It is also widely known that virtualization, as you know it on the mainframe today, was first introduced on the S/360 model-67. This was a “bastard child” of the S/360 processors that had virtual memory extensions. At that point, the precursor to VM/370 used on the S/360-67 was CP-67.

I think you’ll also find that IBM never demonstrated 40,000 Linux virtual machines on a single VM system, it was David Boyes of Sine Nomine, who also recently ported Open Solaris to VM.

Also, there’s no such thing as pSeries Unix in the marketing nomenclature any more, it’s now Power Systems, whose virtualization now supports AIX aka IBM “Unix”, System i or IBM i to use the the modern vernacular and Linux on Power.

Wikipedia is a pretty decent source for information on mainframe virtualization, right up until VM/XA where there are some things that need correcting, I just have not had the time yet.

Oh yeah, by the way. While 2TB of memory on a mainframe gives pretty impressive virtualization capabilities, my favorite anecdote, and it’s true because I did it, was back in 1983. At Chemical Bank in New York. We virtualized a complete, production, high availability, online credit card authorization system, by adding just 4Mb of memory boosting the total system memory to a whopping 12Mb of memory! Try running any Intel hypervisor or operating system on just 12Mb of memory these days, a great example of how efficient the mainframe virtualization is!


Summers over, time for a t-shirt!

My Power 7 and VM/ESA t-shirts

My Power 7 and VM/ESA t-shirts

Over on the mainframe blog, James Governor is talking about start-ups and t-shirt driven development in his latest Redmonk TV. We’ve done the subversive t-shirt thing for years at IBM, both in conjunction with and separately from the SHARE User Group.

When I moved from the UK to the USA, I cleaned out my huge stockpile of t-shirts, both triathlon, running and tech t-shirts and tennis shirts. I kept a few, including the one in the bag on the picture. In the old days getting t-shirts printed couldn’t be done at home and was expensive, so it was common place to keep things obscure, that kept the cost down and the security people away.

The white t-shirt has the IBM 8-bar logo on the left chest, and the numbers 5654-030. Wikipedia currently says that VM/ESA dates from 1988, while that might be true in an intellectual perspective since much of the control program(hypervisor code) came from VM/XA, available in 1988, VM/ESA wasn’t announced until 1990 and the first release 1.0 available in December that year. We wore these VM/ESA t-shirts at that years SHARE meetings, especially at SCIDS.

The other t-shirt in the picture? Well its similarly forward looking, designed and distributed by Richard Talbot around the time Richard and the team got the follow-on processor to P6 through concept. I have a few other t-shirts, maybe we should start a flickr group and post pictures 😉

About & Contact

I'm Mark Cathcart, formaly a Senior Distinguished Engineer, in Dells Software Group; before that Director of Systems Engineering in the Enterprise Solutions Group at Dell. Prior to that, I was IBM Distinguished Engineer and member of the IBM Academy of Technology. I'm an information technology optimist.

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