Quotes of the week [LWN.net]

Quotes of the week

Posted Jun 14, 2012 9:37 UTC (Thu) by jschrod (subscriber, #1646)
In reply to: Quotes of the week by drago01
Parent article: Quotes of the week

> And the reason for wanting a i386 userspace is ... ?

Proprietary programs that are only available in i386 versions.
Or, compliance processes with red tape, needed to approve the architectures switch for an approved installation.
Or, customers with years-old installations, that don't fuzz up the money for the switch project and the associated test costs. (I have one of those customers quite right now.)

> Any sane distribution can run i386 binaries just fine on x86_64.

That's not my experience. Quite often, proper distribution-supported packages (i.e., not roll-your-own installations) for i386 shared libraries in x86_64 base installations are missing. I.e., one has a 32bit program, and no vendor-supported package is available with its needed libraries that can be installed.

And that's because the base install with a 64bit kernel installs 64bit userspace as well. With that come 64bit shared libs packages. Sometimes the distribution offers parallel installs of 32bit shared libs packages. (E.g., -32bit packages from openSUSE. But even there not all shared libs are made available for parallel installs. And no luck at all on RHEL.) Replacing the installed 64bit shared libs packages with their 32bit versions conflicts often with the 64bit userspace that got installed initially.

Of course, I can run my own installation and reconfigure the distribution completely. But that was actually exactly the point that I want to make: I have to do that and it's not readily available. And that's the reason why there is no uptake of the demand that Steven made.

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Quotes of the week

Posted Jun 14, 2012 13:14 UTC (Thu) by nevets (subscriber, #11875) [Link] (2 responses)

You missed my point. I never said that the system should be a x86_64 base, only the kernel. And *that* works just fine on i386 installations.

I've been running an i386 userspace system on an x86_64 kernel since 2005. Never had any issues with it.

Debian today now even supplies a 64bit kernel with its i386 distribution. Although, I think you still need to install the i386 kernel first, and then upgrade to the 64bit kernel after install. The package is:

linux-image-amd64

Quotes of the week

Posted Jun 14, 2012 16:45 UTC (Thu) by jschrod (subscriber, #1646) [Link] (1 responses)

You are right. I didn't know about the linux-image-amd64 package.
So, Debian has the ability to install a 64bit kernel on a 32bit system.

According to http://packages.ubuntu.com/search?suite=precise&arch=..., Ubuntu has no such package.

I know that RHEL 6 and its derivates have no such package, and neither does SLE nor openSUSE. I assume that Fedora has none either.

I'd say, even with this correction, my original statement stands: If one looks at the major distributions, one sees the reason why not more people use such an installation.

Quotes of the week

Posted Jun 14, 2012 16:56 UTC (Thu) by nevets (subscriber, #11875) [Link]

Which gives more reason to add that message.

It will give the major distros more incentive to make their i386 userspace include a x86_64 kernel. Otherwise the kernel will keep calling their users idiots ;-)

Quotes of the week

Posted Jun 14, 2012 22:27 UTC (Thu) by mathstuf (subscriber, #69389) [Link] (2 responses)

> And no luck at all on RHEL.

Hmm? I have i686 and x86_64 packages installed at the same time on Fedora and I remember RHEL 5 being the same. I haven't played with RHEL 6 enough to remember.

Quotes of the week

Posted Jun 14, 2012 23:50 UTC (Thu) by jschrod (subscriber, #1646) [Link] (1 responses)

On an x86_64 system, you can install i686 packages. But then you have already base x86_64 userland packages installed, especially those with shared libs. Additional package installations will cause conflicts with those base-installed packages.

On an i686 installation, no x86_64 kernel package is available, like it is in Debian. "yum list 'kernel*'" tells so.

Of course, you can always create your own completely-self-made-up package list and use Anaconda or AutoYast or such. But this is what I called "roll-your-own installation" above, then you create a spin. It is not an installation mode that is supported by a distribution out-of-the box -- which is what I was asking for.

I don't deny that it ain't possible; after all, one can also always roll one's own kernel and install that. I hinted to the fact that such an installation mode is not widespread because it is *not a mode commonly offered by distributions*.

Quotes of the week

Posted Jun 17, 2012 8:29 UTC (Sun) by drago01 (subscriber, #50715) [Link]

> On an x86_64 system, you can install i686 packages. But then you have already base x86_64 userland packages installed, especially those with shared libs. Additional package installations will cause conflicts with those base-installed packages.

That's just not true.
You can install those just fine ... they won't conflict because the shared libraries go into different directories (lib vs lib64). Which is the whole point of multilib. Binaries in both packages won't conflict either because rpm has a concept of "coloring" which means if you install foo.i686 and foo.x86_64 and both ship /usr/bin/foo it *wont* conflict. /usr/bin/foo will just be the x86_64 one.

Name examples of what you mean. You might just have hit some kind of packing bug for a specific library but they are designed to not conflict and it works fine for me here.

Quotes of the week

Posted Jun 17, 2012 8:33 UTC (Sun) by drago01 (subscriber, #50715) [Link]

> Proprietary programs that are only available in i386 versions.

That does not mean that you need a i386 userspace for them. Multilib works just fine in that case.

> That's not my experience. Quite often, proper distribution-supported packages (i.e., not roll-your-own installations) for i386 shared libraries in x86_64 base installations are missing. I.e., one has a 32bit program, and no vendor-supported package is available with its needed libraries that can be installed.

Not sure what distribution you are referring to but at least on fedora every lib shipped does have a installable i686 counterpart in the repos. So for every libfoo.x86_64 there is libfoo.i686 ...

> And no luck at all on RHEL.

What does that mean? Just install libfoo.i686 (you can do that for every library shipped assuming they are doing the same as fedora which I have no reason to doubt).