Why you can't move a mainframe with a cloud

"Cloud computing is another style of utility computing.... "

" ..Cloud computing is another style of utility computing, but it clusters cheapo servers together instead of using a large monolithic machine "

Well THERE'S your problem, because that is not the definition of cloud computing, you have confused how it's often provided, with what it is.

What it is, is computing resources provided over the internet, usually with contractual conditions where it is provided with matching small increments of cost for small additions of extra use, for short periods of time. Now , I'm sure you could enhance or pick into that definition, but however its defined, the type of computing resources used to provide it should never be part of the definition.

For example, a cloud computing service could equally well be provided by shared use of a stonking great mainframe, as by many cheapo computers. Indeed, going back 40+ years, a mainframe timesharing setup fits the definition of cloud computing.

Power consumption will probably become an increasing factor

Running a traditional mainframe workload on a mainframe uses a lot less power (and space) than doing the same thing on loads of blades. For people who have started measuring their computing needs by the acre, the price tag isn't so off-putting (if it helps negate the risk of a big "Green Tax Axe", clobbering them, somewhere down the line). That's probably an argument for assembling racks more like a mainframes, however, rather than preserving the 'mainframe approach' to computing. A lot of large scale computing, these days, isn't actually done with mainframes.

Mainframe shops are often outsourcing or managed services companies, though, in my experience. So any company saying they "don't use mainframes" - when the entire payroll and HR runs through one that their service partner operates - is a bit like someone withdrawing cash from an ATM and claiming they "have no use for computers". The mainframe approach still has its place, because there's an awful lot of that kind of computing, still to be done, and neither the nature nor he scale of that sort of work is about to change.

As for training the workforce; well - whether things go Cloud or stay Mainframe - anyone coming into the jobs market, with a background in desktop computing, only, will find their skills increasingly irrelevant to the needs of business (the status quo isn't an option). Maybe home programmers will have cut their teeth by renting space form Amazon, or maybe companies will just have to rediscover the concept of training people?

As I see it, the Mainframe's greatest threat is their relatively low turnover. You just don't buy a big Z and expect to be replacing it any time this decade. There comes a threshold, where the renewal cycle is too slow to maintain the supply. To maintain relevance, mainframes will have to become increasingly like Trigger's Broom - where the money comes from a continuing components upgrade, and the occasional sale of a great big box, for the bits to go in. To some extent it's already like that, but then, what is the physical difference between the mainframe, and a rack which has (as it must) adopted a mainframe-like approach to parts-assembly, power consumption and workload?

selling the cloud

Back in the early 90's I was trying to sell the benefits of Microsoft and Unix servers to Legal and General.

The IT manager listened to my pitch and agreed that it was the way to go, but it will never replace the mainframe.

Asking why not he said "Simple the mainframe heats the swimming pool".

ageing

They should be more proactive if they are worried about an ageing workforce. Half of the team I work with in our mainframe shop are under 30. The company has made an effort to train in new staff and retain skills. Any company with a problem that comes down to an ageing skillbase has only themsevles to blame

Vendor lockin

"And somehow, thanks to the vast fortunes that mainframe shops have spent on databases and applications, the mainframes have persisted at thousands of companies."

That is the reason people stay with Mainframes.

There are VERY few work loads where you MUST have a Mainframe. I dont know of any, actually. Performance wise; the Mainframe cpus are 5x slower than a modern x86 (which I have shown earlier with links) so they suck badly. Reliability wise; large Unix/OpenVMS machines and clusters rival that. Price: Unix/OpenVMS are far cheaper.