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Obtaining Mainframe Experience w/o a Mainframe?
Nice2Cats asks: "So I'm reading all over about how companies are desperate for people who know how to work mainframes, especially now that IBM is shipping them with Linux. But how -- short of a course with Big Blue or some other exercise in expensive formal education -- can I acquire even the most basic information or experience with big iron? There doesn't seem to be many tutorials or introductions online; what would be nice, but I can't seem to find either, would be a simulator that would run on a PC. All I want to know is if I like enough to be seriously interested."
yet excellent page on just this topic. :)
HERE
Hope this helps!
For every annoying gentoo user, are three even more annoying anti-gentoo crybabies. Take Yosh from #Gimp for example.
Hercules was created by Roger Bowler and is maintained by Jay Maynard. Jan Jaeger designed and implemented many of the advanced features of Hercules, including dynamic reconfiguration, integrated console, interpretive execution and z/Architecture support.
"Flyin' in just a sweet place,
Never been known to fail..."
At least, that's the theory. After doing a fair amount of mainframe work, mostly with VM/CMS, I got to the point where the extreme weirdness of the environment was kind of cool in a retro sort of way, and I began to get a sense of how it all fit together. But this is not something you're going to pick up from a tutorial on the Internet.
:'}
Basically, if you want to do mainframe stuff, you should find someone to hire you who needs some work done and doesn't mind paying you to learn, and then *don't assume you know what you're doing*. Even the way terminals and serial ports work is different. Many of the basic assumptions about how operating environments work are different on mainframes. CPU time is not free - if you accidentally run a spin loop, it can cost thousands of dollars very quickly.
It's a very weird environment...
It wouldn't surprise me if there were a 370 emulator out there, but where are you going to get the software to run on it?
AS/400's come up on ebay all the time. Maybe a little small for your definition of a mainframe, but they will fit in your apartment.
"Eve of Destruction", it's not just for old hippies anymore...
IBM has pretty decent documentation on their stuff, at least the AS/400 docs were good.
Go here for the zSeries and S390 docs.
"From my cold, dead hands you damn, dirty apes!" - CH
I'vebrought up Hercules at home and it does a good job at the HARDWARE level. the real issue is that of getting an O/S that you CAN run.
Older versions of MVS (ie MVT) are available, as are older versions of VM. However, these run in 370 mode, not in ESA or Z mode.
I'm not sure about what Linux versions would run on this emulator.
It is though still a good means of gaining some familiarity with the environment.
Perhaps counterproductive for your carrier, but I've ran into an impressive array of Mainframe and Minicomputers in the Navy, particularly in the Intelligence/Cryptology field. At the tender age of 19, I was assigned to administer a PDP11/70 based broadcast server. I was given a full bookshelf of manuals, and told "go figure this out..". This was 1994. I still have the faceplate from that beast from when we decommissioned it. Next in my parade of obsolete equipment was an AT&T 3B2/600 running SVR4. Not exactly "Mainframe" material, but old and cranky regardless. Then a VAX server monster running VMS. In a big ugly building in Hawaii, all sorts of ancient IBM, DEC, SGI, Sun, Hp and even Cray are still alive and well. Typically the Navy assigns one SYSADM to a big mainframe, issues them a pager, and wishes them good luck. You'd be amazed how quickly you learn something when you know that you are the only one available (with the proper security clearance) to fix something, and your not getting to sleep until it's done. I've found that the factory manuals are pretty good. Hard to read and dry as a bone, but the important stuff is all there. I haven't checked eBay, but that might be a place to start. Often, defense contractors hire technically inclined individuals for part time employment. You'd be amazed at the kind of hardware you can get your hands on with that sort of job. Getting the required security clearance is the only real hurdle.
There's a free mainframe emulator, but the available operating systems for it are either Linux-based or obsolete IBM operating systems. IBM still charges very high prices for their current mainframe operating systems.
It's a pure interpreter written in C, and thus slow; emulation costs you about two orders of magnitude in performance. But that gives you the performance of an entry-level IBM mainframe circa 1998 or so.
There's a commercial emulator called FLEX-ES, but if you have to ask how much it costs, you can't afford it. It's being sold to companies who are replacing old IBM mainframes with an emulator running on an x86 rackmount server. IBM will license their OSs for FLEX-ES, as long as the emulated CPU doesn't exceed 8 MIPS (!).
Two or three years ago there was a consulting firm that rented time on their AS400 for not very much a month advertising on the AS400 newe group. Hop over to groups.yahoo.com or your favorite newsreader and do some looking there. Ask -- it's quite friendly as usenet goes.
:Redbooks and Redpapers -- that's what they call techical whitepaper, and they're a good resource.
IBM publishes all their reference manuals for both the iSeries and zSeries OSs on line for free access. Go to www.ibm.com and search around for eSeries, OS400, OS390 and Reference. Also search around for
In my city, and I expect in others, the local two year community college teaches extension courses in what we used to call "Data Processing". Basic Tape Monkey and Console operator courses in mainframes and AS400s. JCL, CL, maybe a bit of Cobol, RPG, or some SQL queries. Nothing fancy, but the courses are hands on. These classes would not necessarily be for college credit - perhaps for adult education CEUs. Fees don't seem particularly expensive.
This is obviously dependent on your local CC's resources, interests, and local demand. But check it out.
http://publib-b.boulder.ibm.com/redbooks.nsf/porta ls/S390
I'll hand this much to IBM. They put out *tons* of documentation for free. It's not a ground-up overview followed by specific, real-world instruction. But, having attended more than a few AS/400 classes (no, it's not a mainframe... it's a midrange), I can tell you the instructor says "Here's your CD of Rebooks. Read them from cover to cover. This class is only to give you an overview of what you will find in them."
So, you don't go interview someplace and say "it's ok... I read the manual." But it's a starting place. And, you'd certainly sound more credible in an interview if you said "I have years of OS experince in open systems. My zSeries knowledge comes from reading Redbook X, Y and Z, and I want to learn more." Chances are, the mainframe guys have the books on their bookshelf. And, knowing the mainframe people, they refer to them.
Amateurs discuss tactics. Professionals discuss logistics.