Linux Possibly Ported to IBM Mainframes

Jah-Wren Ryel writes " Vnunet is reporting that IBM has a version of Linux ported to their S/390 mainframe architecture waiting in the wings. Apparently there are two versions, one that runs under VM (a kind of meta-os, sort of like VMware) and one that runs on the bare hardware." An "anonymous source" and "speculation from analysts" story. Nothing official from IBM. Please read and judge accordingly.

Comments

Linux/390 is a lot older than you think...

[RISCy Business]

...take it from someone who's discussed it with the guy who actually started it. Linux/390 isn't very special, really. When I last spoke with him (I'm sorry, I've forgotten his name.. I forget names easily. :P) it just ran on the bare hardware, and didn't support much at all. If anything.

Now, some info on the S/390 from someone who's not gotten to play with one, really, but has seen one.

The S/390 is a 'massively parallel' computer. Meaning that everything is parallel. The S/390 is capable of running just about any OS you throw at it, from Linux on an x86 host controller to Windows NT on that same host controller. You can run AIX on an RS/6000 host controller. Or OS/400 on the AS/400 host controller. It's designed to do massive processing while serving up literally thousands of hosts. Usually 'dumb' terminals over twinax (twin-prong coaxial), triax (three-prong coaxial), or RS232/RS242.

No, it's not meant to run Linux instead of OS/390. I wouldn't dare to say that it should, because in truth, it shouldn't. The S/390 is not a 'convenience' machine or a 'play' machine. It is a mainframe, and it needs a mainframe OS.

However, I see absolutely no reason why Linux shouldn't run on the S/390. Bear in mind; running on the S/390 does not mean replacing OS/390. It means SUPPLEMENTING OS/390. Say you have an S/390 handling most of your financial transactions, but accounting wants a website to keep track of it. Running Linux on an x86 host controller on an S/390 is the perfect solution. But say accounting wants to cut some major expenditures out of the budget; eliminating OS/390 isn't a good idea. Plain and simple.

OS/390 is a *VERY* mature OS, pretty much dating back to OS/360 (the similarities between OS/390 and OS/370 are very obvious) and as a direct result, is rock solid stable, extremely secure, and inherently reliable. Add that in to hardware that is designed to have decades of uptime. Add in the power to get the job done and then some. That's what the S/390 is about. It's a big-bucks big-iron machine meant to be your network-edge solution for ERP and transactions and whatever else you want to throw at it. It's not your webserver, it's not your fileserver. It's a mainframe.

However, I've noticed quite a few people are moving away from S/390 to the actually more powerful RS/6000's, which lack some of the features of the S/390. Okay, MOST of the features people look for in the S/390. Some RS/6000 models border on the commodity machine definition. Linux doesn't belong there, either. Yes, that's right, you're hearing it from someone who spends about 99% of his spare time working on porting Linux more thoroughly to the RS/6000. Linux doesn't replace AIX. Period. AIX is a mature OS, probably 7 or 8 years Linux's elder. AIX has a very stable and regular release and development cycle, and is built on principles that have been proven a million times over. It's inherently reliable, stable, and very fast. Unlike Linux, AIX does not just have 'general' releases for all RS/6000's with all architecture support. There is AIX for the RS/6000 F40 (Dual PowerPC 604e) and there is AIX for the RS/6000 Power260 (single POWER3). You can't mix and match those two or components from them. AIX is optimized at the hardware level extensively. Unlike my work, it's built on native platform, optimized on that platform, and meant for that platform.

Yes, every piece of AIX has a common code base. The compilers do the work. That's why it's built on the native platform. You can get AIX C/C++ compilers for PowerPC 604e, POWER2, POWER3, and so on. And they're designed to optimize and compile reliably. ANd they do it well. Better than gcc or egcs could ever hope to.

Linux/390 is a great project. Like I said; there's no reason whatsoever that Linux should NOT be able to run on the S/390. There's no reason Linux should not be able to run on ANY system. The question is, though, do you want to replace what that system is MEANT to run with Linux?

Not yet. Linux is still a long way off from being ready to do that. But maybe someday it will be ready.

-RISCy Business

Old News/More Info

[DragonHawk]

This is Old News, in computer terms.

LinuxToday ran a story on this back in mid-October. In it, they referenced an article in the Danish version of ComputerWorld. The feedback comments to LinuxToday are interesting, and several of them pointed out one project's home page.

Mainly to run Linux in parallel with other OSes

[DragonHawk]

What would the purpose of this be?

As the article says (you did read the article, right? *grin*), the main point would be to run Linux in parallel with other S/390 OSes like MVS. As everyone seems to be pointing out, Virtual Machines are very popular in the mainframe world, and it is quite common to run more then one OS at a time. Thus, Linux would be just one more OS.

The suggested application was Lotus Domino. I can also see web servers, application servers, general Internet servers, that sort of thing, being useful. Perhaps a company running a big back-end mainframe database would want to use Linux for the front-end interface, with (for example) Cold Fusion. I can see quite a few uses for it.

Is a big bank going to dump MVS and move to Linux on the S/390? No, of course not. That isn't the point.

Plus, there is hack value. We can now say with a fair amount of confidence that Linux is the most scalable OS on the planet. It runs on everything from large IBM mainframes to hand-held Palm Pilot devices.

I'll believe it when I see it.

It is already partly done, from what I understand. My comment here has links with details.