Talk:Linux on zSeries

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[edit] 31-bit or 64-bit

31 or 32 bits mode?

When Linux on zSeries is running on s/390 (31-bit hardware) then Linux can only run in 31-bit mode. When running on zSeries (64-bit hardware) then Linux can run in either 31-bit or 64-bit mode.

31. The mainframes never had a 32-bit mode. It is more accurate to say that the mainframes never had a 31-bit addressing mode (the registers were 32-bit however). It shifted from 24-bit to 31-bit (the last bit indicating the used addressing mode) with the ESA architecture.

Actually XA introduced 31-bit addressing and was supported by MVS v2 in the early 1980's. ESA introduced access registers increasing the addressing range horizontally rather than vertically. It was supported by MVS v3 in the later 1980s.

You're right for MVS/XA (I read my history notes). The first part of my post is accurate however. If I do not make mistake, access register are used to address address spaces?

Yes, everything you said was correct, esp if you substitute ESA with XA. access register mode allowed (and still does) addressing to address spaces and data spaces (which are like address spaces but were never originally an address space, so they only contain data as opposed to executable code, but can be shared or accessed by other address spaces ... esp if you know how to manipulate the address translation tables'-) Thus the `horizontal' analogy; being able to address multiple address/data spaces in 31 bit mode at the same time.

I apologize, these are my first entries to a wiki so I don't know how to attribute the comment to myself or how to format the discussion thread properly.

If you are Linas, then I had some correspondence with you while bigfoot was still going strong. Today I amuse myself working on the hercules emulator. --[gsmith]

I'm not Linas, sorry.

I wanted to refer to data space when I said address spaces... I never used those though. the only assembler programs i did were less than 4096 bytes :)

>I don't know how to attribute the comment to myself or how to format the discussion thread properly.

No problem, me neither.

About Hercules, I never tried to run the emulator. It seems complicated to set up. At my shop, we're installing some linux on Z/VM. With Hercules, I could theorically emulate a single S/390 Linux image legaly on my PC, no? --[fred]

IANAL, but I believe you are talking about running GPL'ed software, so I see no reason why not. --Maru (talk) Contribs 04:09, 5 November 2005 (UTC)

Thanks --142.213.160.67 14:36, 7 November 2005 (UTC)

[edit] NPOV?

This article reads very much like an IBM ad... --Liam Proven 19:54, 11 July 2005 (UTC)

Probably because 80% of the anon contributors are IBM employees. But is there something in particular you object to? Something you think is incorrect? Don't just say its POV without saying what's wrong with it. --linas 22:20, 7 October 2005 (UTC)

Ok, I went through and improved it. Is it any more NPOV now? --Maru (talk) 01:57, 8 October 2005 (UTC)

While it seems slightly more neutral now, you've changed concrete statements to softer statements that aren't true. For example you said "IFL hardware tend to be less expensive than general purpose engines (CPs)."

There is no question that IFLs are always cheaper for running Linux than full CPs, hence the reason they exist. Saying they tend to be is incorrect.

You also added that "Like most other versions of Linux , Linux on zSeries is governed by the GPL"

As far as iI know, there are no versions of Linux that aren't governed by the GPL.

I have no idea what IFLs are compared to GPUs, so I erred on the side of NPOV. If you know what the deuce those are, then please feel free to change that. And there are indeed versions of Linux effectively not governed by the GPL. The GPL only applies to software publicly relelased (the P in the GPL). So Google's version of Linux could well be under some crazy Google license, since AFAIK they do not release the binaries publicly. If they did though, and tried to keep it under their crazy license, all hell would break loose, so it is a curious loophole, but largely of little relevance (though I hear GPL v3 is going to address services, closing that loophole). --Maru (talk) 04:29, 9 October 2005 (UTC)

That's not right, google is still obligated under the GPL. They cannot put their version of Linux under "some crazy Google license". (However, they do not have to disclose their source modifications). linas 04:47, 5 November 2005 (UTC)

Looks like the last little bit of edits put back a bunch of the marketing-speak. Jay Maynard 16:59, 12 May 2006 (UTC)

I disagree that this reads like marketing. IBM has a schizophrenic attitude toward zLinux. They want Linux users to migrate to mainframe Linux, but they do NOT want mainframe zOS or zVSE users to migrate to zLinux. Why? IFLs provide the same CPU capacity as general purpose CPUs at ~1% of the price, restricted to zLinux (and zVM). So, while this information is available, it is poorly understood, and this article goes a long way toward correcting that. I was very surprised at its thoroughness, and I think it is providing a unique and needed service. And I have absolutely no connection to IBM personally, though I do work with ports from mainframes to zLinux.

Okay -- sorry -- I have nothing against IBM, but Jay is right. This reads like a frigging brochure, not an encyclopedia entry. I think about 70 percent of this material should go. Rhombus 18:07, 20 January 2007 (UTC)

I'm not sure it should go, really...but it definitely needs a rewrite. If I get some free time this week, I'll take a crack at it. Jay Maynard 15:59, 21 January 2007 (UTC)

[edit] Running on Hercules

I think the existing language violates NPOV, since there's only one person who's ever raised the issue of whether Hercules violates any IBM patents. See, especially, the undue weight section of that page. IBM itself has never approached anyone with such a concern. Further, this page is not the place to discuss those concerns, as they're not specific to Linux.

I propose replacing the language with this:

The open source Hercules software is also available. While Hercules is not sanctioned for running licensed mainframe operating systems, such as z/OS, software licensing issues do not apply to running Linux on Hercules.

If someone thinks that the patent issues are that important, then an NPOV discussion can be added to the Hercules entry.

-- Jay Maynard 16:52, 15 May 2006 (UTC)

[edit] zUbuntu

The article should probably have something on zUbuntu, the Ubuntu port for zSeries. --Easyas12c 18:33, 15 June 2006 (UTC)

Is there anything beyond an original project announcement? Has any actual work been done? Jay Maynard 19:26, 15 June 2006 (UTC)

[edit] Large installation

While 1700 installs might be large considering how many mainframes that are still out there, it's not a large user base. —The preceding unsigned comment was added by 216.136.85.66 (talk) 01:19, 7 December 2006 (UTC).