Debian TC vote on init system coupling

Posted Feb 24, 2014 9:01 UTC (Mon) by heftig (subscriber, #73632)
In reply to: Debian TC vote on init system coupling by nim-nim
Parent article: Debian TC vote on init system coupling

I don't see how this is a problem.

Systemd would be pinned at a certain version (plus backported fixes) for the entire release. You would only get a major systemd upgrade as part of a release upgrade, which comes with loads of other upgrades such as a new kernel.

You'd have to be crazy not to reboot.

Debian TC vote on init system coupling

Posted Feb 24, 2014 15:53 UTC (Mon) by mgb (guest, #3226) [Link] (24 responses)

Debian used to be able to smoothly upgrade not just init but entire systems from one major release to the next without a reinstall and only one reboot. The Fedora/systemd plumbing layer has never been smoothly upgradeable.

The only serious pothole affecting Debian upgrades in recent years was of course udev. Udev incompatibilities doubled the amount of work involved in upgrading Debian from one major release to the next.

But now Debian has systemd - udev on steroids. Systemd's plumbing warts and interference with well-behaved packages are already hurting Debian.

Debian TC vote on init system coupling

Posted Feb 24, 2014 16:04 UTC (Mon) by anselm (subscriber, #2796) [Link] (18 responses)

You must be running a Debian that is significantly different from mine. I've been upgrading loads of Debian systems ever since way before udev even existed, and I have yet to experience even one upgrading snag that was attributable to udev.

Debian TC vote on init system coupling

Posted Feb 24, 2014 17:13 UTC (Mon) by mgb (guest, #3226) [Link] (17 responses)

the udev version in lenny will not provide all the functionality expected by the latest kernels, special care must be taken when upgrading to avoid putting your system in an unbootable state.

Booting the 2.6.26 kernel from lenny with the udev from squeeze may result in a failure to correctly assign names to network devices, and will also fail to apply certain additional permissions to block devices (such as access by the disk group). The software itself will appear to be working, but some rules (for example, network-based rules) will not be loaded properly. It is therefore strongly recommended that you upgrade the kernel on its own at this point, to ensure a compatible kernel is available before upgrading udev.

Debian TC vote on init system coupling

Posted Feb 24, 2014 17:34 UTC (Mon) by anselm (subscriber, #2796) [Link] (16 responses)

So? In my book, upgrading a Debian system means reading the release notes and following what they say. So you upgrade the kernel first. Problem solved.

Also, please explain how the issue you cited is udev's fault, other than by virtue of its mere existence. You could argue that without udev this problem wouldn't occur in the first place, but on the other hand udev is so useful in day-to-day life that paying attention when doing a stable-Debian upgrade (something that happens once every two years or so) is probably worth our while.

Debian TC vote on init system coupling

Posted Feb 24, 2014 17:56 UTC (Mon) by mgb (guest, #3226) [Link] (15 responses)

Poorly designed plumbing interferes with robust upgrades.

Systemd is far more intrusive and disruptive than udev.

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:07 UTC (Mon) by HelloWorld (guest, #56129) [Link] (14 responses)

Systemd supports old tools like service, update-rc.d, chkconfig, telinit, it supports init scripts better than sysvinit ever did (cgroups make this more robust, LSB headers are honored properly), even cruft like /dev/initctl and wtmp/utmp is supported. How is that disruptive?

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:24 UTC (Mon) by mgb (guest, #3226) [Link] (13 responses)

Are you familiar with Fedora and Debian plumbing? Systemd have made it very clear that they are not going to support both.

Systemd distros will migrate to Fedora plumbing elements whenever systemd so dictates - a huge loss of Debian functionality.

And systemd have further made it very clear that they will continue to "standardize" additional plumbing whenever they feel like it - leaving Debian struggling under an endless deluge of systemd bikeshedding.

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:43 UTC (Mon) by rahulsundaram (subscriber, #21946) [Link]

" Systemd distros will migrate to Fedora plumbing elements whenever systemd so dictates - a huge loss of Debian functionality."

I have already pointed this out to you but systemd is not carrying over Fedora plumbing at all. Fedora moved to the things that systemd standardized on, many of which were adopted from Debian and none were adopted from Fedora!

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:44 UTC (Mon) by anselm (subscriber, #2796) [Link]

Systemd distros will migrate to Fedora plumbing elements whenever systemd so dictates - a huge loss of Debian functionality.

I don't think this is in fact true. Various parts of systemd's plumbing have been patterned on Debian even before Debian decided to adopt systemd as its default init, because the Debian approach was better than what Fedora had at the time.

I think in the long run the plumbing will gravitate to whatever is best for the job at hand. If Debian has a better approach to some plumbing issue than Fedora, it ought to be possible to convince the systemd developers that this is in fact the case, and nudge systemd towards the Debian way of doing things. They're not stupid, after all, and they're interested in technical excellence, not in making everything Fedora. In other cases whatever Fedora does may actually be superior, and it is entirely appropriate to base systemd's plumbing on Fedora. Or SUSE. Etc.

Anyway, more Debian involvement in systemd means that Debian's approaches and wishes will be that much better understood by the systemd community, which is to everybody's benefit given that Debian, like systemd, is committed to technical excellence.

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:53 UTC (Mon) by HelloWorld (guest, #56129) [Link] (10 responses)

> Are you familiar with Fedora and Debian plumbing? Systemd have made it very clear that they are not going to support both.
systemd doesn't care where the plumbing comes from, it just tries to pick the most sensible alternative. And in quite a few cases, they adopted debianisms, which were then also adopted by Fedora.

> Systemd distros will migrate to Fedora plumbing elements whenever systemd so dictates - a huge loss of Debian functionality.
systemd can't possibly dictate anything, it's just an open source project, and also new functionality in systemd doesn't mean that the equivalent features in debian somehow magically disappear. In short, what you're saying here is nonsense.
In fact, if debian has a better implementation of something, the sensible thing to do is to try to push it into systemd, so other distros eventually end up offering it to their users too (except if they go out of their way to disable it). Everybody wins that way.

> And systemd have further made it very clear that they will continue to "standardize" additional plumbing whenever they feel like it - leaving Debian struggling under an endless deluge of systemd bikeshedding.
WTF? Sometimes storing the hostname in /etc/HOSTNAME, sometimes in /etc/hostname and sometimes in /etc/sysconfig/network, *that's* bikeshedding. It's a huge win that systemd stops that kind of madness.

Debian TC vote on init system coupling

Posted Feb 25, 2014 1:19 UTC (Tue) by rahvin (guest, #16953) [Link] (9 responses)

I get why you are replying but he's doing the Redhat is evil troll that these threads have been dominated with and I think you are missing it.

I have no idea how anyone could feel that way but it's clearly her/his point of view and it's rather pointless to even discuss facts because the facts really aren't relevant to the point he/she is trying to make, which is Redhat is evil. You'd have better luck trying to have a philosophical discussion with an inanimate object.

Debian TC vote on init system coupling

Posted Feb 25, 2014 4:44 UTC (Tue) by mgb (guest, #3226) [Link] (8 responses)

Strawman eh? Evil doesn't enter into it.

Fedora is different. It works better for some people. Debian works better for some people.

Replacing Debian plumbing with Fedora/systemd plumbing is a serious loss.

Debian TC vote on init system coupling

Posted Feb 25, 2014 5:56 UTC (Tue) by rahulsundaram (subscriber, #21946) [Link] (2 responses)

" Fedora/systemd plumbing"

To be honest, you want to call that Fedora/RHEL/Mageia/openSUSE/Arch plumbing instead of pretending it is Fedora specific.

Debian TC vote on init system coupling

Posted Feb 25, 2014 6:07 UTC (Tue) by mgb (guest, #3226) [Link] (1 responses)

What is it with systemd advocates and strawman arguments?

Nobody is claiming there's anything unique about Fedora plumbing.

However Debian/Ubuntu/etc plumbing is different, many but not all people find it better, and replacing it with Fedora/systemd/etc plumbing is a massive loss.

Debian TC vote on init system coupling

Posted Feb 25, 2014 6:23 UTC (Tue) by rahulsundaram (subscriber, #21946) [Link]

" What is it with systemd advocates and strawman arguments?"

Ironically, that is a big strawman by itself.

" Nobody is claiming there's anything unique about Fedora plumbing."

If you don't mean to imply that, you should avoid writing Fedora/systemd that gives that impression you are trying to equate these two projects. If you want to attach distros to the systemd project, then you want to list all the distros that use systemd instead of singling out Fedora.

Debian TC vote on init system coupling

Posted Feb 25, 2014 8:48 UTC (Tue) by anselm (subscriber, #2796) [Link] (2 responses)

Replacing Debian plumbing with Fedora/systemd plumbing is a serious loss.

Which is why nobody is proposing to do this, at least not in a way that does cause »serious loss«.

First of all, »systemd plumbing« is not necessarily »Fedora plumbing«. Considerable parts of »systemd plumbing« actually derive from Debian, or from other Linux distributions.

Secondly, in many cases it doesn't actually matter. For example, whether a system's host name is stored in /etc/hostname, /etc/HOSTNAME, or /etc/sysconfig/hostname is quite immaterial, and it is hard to argue that one approach is technically superior to another. Which is why the standardisation that systemd catalyses is overdue and very welcome.

There are cases where it makes sense for Debian to stick with »Debian plumbing«, e.g., for compatibility or because the Debian approach offers more features than the systemd default. In these cases it is generally easy to disable/mask or override the systemd default, with a view to possibly integrating whatever Debian does into upstream systemd if it is of general interest.

I'm personally confident that the systemd developers and the Debian systemd maintainers are going to come up with a way of providing systemd for Debian that will let us take full advantage of the stability improvements and new features that systemd enables. There will not be »serious loss«. Two or three years from now we will look back and wonder what all the fuss was about.

Debian TC vote on init system coupling

Posted Feb 25, 2014 9:41 UTC (Tue) by bangert (subscriber, #28342) [Link]

> Considerable parts of »systemd plumbing« actually derive from Debian, or
> from other Linux distributions.

And that even though Debian had not committed itself to systemd at that point. I take this as a clear indication of the systemd developers being committed to technical excellence and their willingness to cooperate...

... or, if that does suit your world view, it could be an effort to bribe Debian into adopting systemd.

Debian TC vote on init system coupling

Posted Feb 25, 2014 14:31 UTC (Tue) by mebrown (subscriber, #7960) [Link]

For all that I love the LWN comment system, especially the commenters, sometimes wish there were an easy way to +1 all of your comments! They have been patient and detailed, rather than FUD or trollish. Thank you.

Debian TC vote on init system coupling

Posted Feb 25, 2014 14:28 UTC (Tue) by mebrown (subscriber, #7960) [Link]

Why do you keep repeating the same thing over and over and over, when the previous person responded to you in a very detailed manner explaining why you were incorrect?

Asserting this over and over does not make it true and moves my mental slider for your comments further into troll territory every time you repeat the same thing without offering anything new.

Debian TC vote on init system coupling

Posted Feb 25, 2014 15:00 UTC (Tue) by Chousuke (subscriber, #54562) [Link]

You keep calling it a serious loss but you haven't actually provided an argument as to why.

I've been running systemd as a default init for a long while on my Debian laptop now (and finally uninstalled sysvinit a shorter while ago when the package dependencies no longer prevented it) and it's been working perfectly.

Debian TC vote on init system coupling

Posted Feb 24, 2014 16:12 UTC (Mon) by palmer_eldritch (guest, #95160) [Link]

I believe you can trust Debian not to release the next stable until the update process goes smoothly, no matter what software they use in the distribution. Even if it means releasing later than previously scheduled.

Debian TC vote on init system coupling

Posted Feb 24, 2014 16:33 UTC (Mon) by fandingo (guest, #67019) [Link]

I think that you fail to recognize that systemd development is entering a new phase with the upcoming release of RHEL 7. There will certainly be a greater focus on backporting fixes and easier upgrades in the future. (Although to be honest, I've never experienced any of the problems that you describe.)

Debian TC vote on init system coupling

Posted Feb 24, 2014 18:29 UTC (Mon) by rodgerd (guest, #58896) [Link] (2 responses)

> Debian used to be able to smoothly upgrade not just init but entire systems from one major release to the next without a reinstall and only one reboot. The Fedora/systemd plumbing layer has never been smoothly upgradeable.

Really. I guess that's why the libc->glibc transition resulted in me having to reinstall Debian boxes from scratch, because of Debian's perfect record on smooth upgrades. And when I couldn't boot some servers after the MD tool changeover left me with non-starting software RAID arrays, that was an exemplar of Debian's perfect upgrade process, too, was it?

Debian TC vote on init system coupling

Posted Feb 24, 2014 19:59 UTC (Mon) by malor (guest, #2973) [Link]

He made no claim that it was perfect; that was all you. He merely said that it was good, and that udev added a lot of work to the upgrade process, both of which are true, as far as I know.

And, fer chrissake, the glibc transition was fifteen years ago. You could probably let that go. I don't think any distro did well with that particular mess. The conversion from a.out to ELF, even earlier, was also very disruptive. Debian has, pretty consistently, been the least painful distro for upgrades, but least painful != painless.

If you believe that Debian sucks horribly at upgrading, why on earth would you think making it worse would somehow be a good idea?

If your argument is that it won't, in fact, be worse, because of a bad experience you had a decade and a half ago, that's not very persuasive, either.

Debian TC vote on init system coupling

Posted Mar 1, 2014 6:48 UTC (Sat) by k8to (guest, #15413) [Link]

This was in the era where Red Hat 5 or 6 (whichever shipped with glibc) segfaulted in common binaries on fresh install with no hardware errors.

Really everything was pretty fubar around that transition point, even without upgrades, so I wouldn't put too much weight on that scenario from 1997 or so.