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How to Crash Systemd in One Command

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Re: How to Crash Systemd in One Command

#151

Post by digi_owl »

korethr wrote: post #145
digi_owl wrote: post #115

Earlier quoted context omitted.

Best i can tell, Poettering cooked up PA back when ALSAs dmix was something you manually enabled on cheap soundchips. Frankly i think it would have gone nowhere if Canonical didn't decide they needed to copy Windows' "one volume slider pr program" thingy that was introduced in Windows 7 or there about. Note btw that these days Poettering is no longer involved with PA development. BTW, the main goal of systemd seems t…

I find the 'one slider per program' frequently useful. Different programs can be outputting at wildly different levels. I might have my music playing at a comfortable volume, then discover a video on YouTube I want to watch, and it comes in painfully loud, such that I'm immediately reaching for the volume control on the speakers or yanking off my headphones. Then when the video's over, I get to turn my speakers/headp…

Frankly the problem there is that browsers, even though they are becoming a second OS, do not have a central volume control. Heck, i swear Youtube resets the volume setting at near random (or maybe its some kind of insane AB testing?).

Re: How to Crash Systemd in One Command

#152

Post by Sanddancer »

georgyo wrote: post #73
mjevans wrote: post #59

Earlier quoted context omitted.

There are exactly two compelling (for me) arguments against systemd, and one that seems to result from it's current focus: * Binary log files (WHYYYYY; OTOH you could argue that the only proper place to do logging is to a remote database.) * Monolithic nature - everything gets shoved in to the daemon, making it harder and more unusual to do things without it. * Servers - systemd seems to be focused on a desktop lifec…

All of these are false. It stores everything in binary logs, however your old system didn't store it at all. You had a daemon (syslog, rsyslog, etc) that wrote them as plain text. If you start those daemons, you at exactly the same spot as before. Just with an additional copy in a binary log. Which btw, journalctl can do some magical things, and you should take some time to play with it. systemd is not monolithic, or…

If you had a basic syslog setup, it stored as text files. However, a more interesting syslog setup would take those entries and send them to a remote database, filter them to match certain contents, run scripts based on those matches, etc. Systemd only seems magical because most distros don't use even a sliver of the abilities that modern syslogs provide.

Systemd is a Jenga tower. Yes, there are lots of little pieces, and yes, removing a few won't hurt anything, but it's still fragile, and rather inconsistent. "Parts" like the journal, are a separate executable, but are not managed like other services. It uses a poorly documented ipc interface to talk to the various parts, and the configuration files are a nasty tangle of symlinks and control files stretching across the filesystem. It's just not a very well engineered piece of software.

Re: How to Crash Systemd in One Command

#153

Post by m45t3r »

rascul wrote: post #139
m45t3r wrote: post #123

You could simple do a DoS attack with a local user using a fork bomb too. It would be even shorter than the command showed in this post blog. So while this is a bug, the author is overreacting just to make systemd look bad.

your fork bomb can be mitigated with ulimit

I am not saying that this is not a bug, just that this isn't the problem that the author is making. If you have local access, you probably can do other things if your only objective is to do a DoS.

Re: How to Crash Systemd in One Command

#154

Post by wott »

rhinoceraptor wrote: post #129
1_2__3 wrote: post #96

Earlier quoted context omitted.

Can we please just have one OS we use in data centers and servers whose features and development is guided by professionals, not rubes? I'm so sick of people telling me I'm not the target user or some variant thereof. Linux is not OSX or Windows, and not swayed by arguments of the form "most people don't are about that". I do. They should. And the fact that they don't shouldn't result in crappy operating systems.

You're free to use Linux (or BSD or Illumos for that matter, have fun!) with any init you want. For every person whinging online about systemd, there are hundreds of people using it every day in their laptops and servers without giving it a second thought.

Without having given it a first thought either.

Re: How to Crash Systemd in One Command

#155

Post by wott »

justinsaccount wrote: post #130
fapjacks wrote: post #74

Earlier quoted context omitted.

Yes, these are also reasons I dislike systemd. Also, one of the original selling points of systemd was "It will reduce boot times significantly!" ... And then it ends up that systemd is actually slower to boot than any of the other ones out there.

> Also, one of the original selling points of systemd was "It will reduce boot times significantly!" It was not. http://0pointer.de/blog/projects/the-biggest-myths.html Myth: systemd is about speed.

No, that's revisionism, Poettering rewriting history.

Re: How to Crash Systemd in One Command

#156

Post by snorrah »

sparewalking wrote: post #141
gaius wrote: post #45

Earlier quoted context omitted.

Systemd is winning because they showed up and basically nobody else did. Systemd is "winning" because Red Hat are throwing money at it as a way to control the ecosystem.

Red Hat refused the project initially.

But after the Fedora Technical Committee were convinced to accept it, it ballooned from there. Seed blossomed from within.

Re: How to Crash Systemd in One Command

#157

Post by xaduha »

ultramancool wrote: post #54
zdw wrote: post #9

Earlier quoted context omitted.

Alternatives have been implemented before: http://cr.yp.to/daemontools.html http://smarden.org/runit/ The more you look at any of DJB's software, the more of the future you'll see.

I've switched everything I write to use runit because runit doesn't require any particular init system, you can easily integrate it with sysvinit, freebsd's RC, ubuntu's upstart, systemd, etc. It just runs on top and doesn't need to be the king and it's incredibly simple to write scripts for it. Completely removes the need to worry about this init mess.

I did too. At one point. Then I abandoned all that in favor of NixOS. It uses systemd and I don't care.

Re: How to Crash Systemd in One Command

#158

Post by thescribe »

justin_vanw wrote: post #3

It seems like it is quite fashionable to hate on systemd, and it seems like systemd is kindof a piece of crap - in some ways. However, linux is missing basic functionality other os's offer, and systemd is showing up and trying to fill in those blanks. This is open source, if you don't like systemd, if you think it's crap, if you think there are obviously better ways to do it, well, what are you waiting for then? Syst…

I'm not sure forking would be worthwhile, I think the issue people have with systemd is one of goals and structure of the operating system. Any fork that satisfied the other side would not even be in the same category of software.

Re: How to Crash Systemd in One Command

#159

Post by thescribe »

geofft wrote: post #18
lasermike026 wrote: post #14

Earlier quoted context omitted.

The Unix philosophy: Write programs that do one thing and do it well. Systemd doesn't observe the Unix philosophy and that bothers many people.

It's baffling to see people insist that that's the UNIX philosophy when the UNIX philosophy has always been about monolithic kernels over microkernels, so "do one thing" is out the window, and about worse-is-better over do-the-right-thing ( https://www.dreamsongs.com/RiseOfWorseIsBetter.html ), so "do it well" is out the window. And the userspace tools don't follow this either. Quoting http://prog21.dadgum.com/139.ht…

Instead of talking about Unix philosophy let me put it this way. I love whitebox components I can swap out for competing components. Systemd threatens that for me.

Re: How to Crash Systemd in One Command

#160

Post by ultramancool »

dijit wrote: post #95
ultramancool wrote: post #48

Earlier quoted context omitted.

The thing is though - their code is already written. Systemd is entirely unnecessary for 99% of people, probably everything except some of it's LXC features has clear and popular alternatives. LXC is the only thing making me eye systemd with interest, but I'll come back to it in a few years once all the weird stuff is worked out.

It's nice to hear that you have the choice of not running systemd. All production ready Linux distros (RedHat (and by extension CentOS), SuSE and Debian) are all running systemd and as a systems administrator for a large company I _must_ adopt it, I don't have a choice.

If those major distros weren't switching though, you wouldn't have to, which is what my point was. The only reason you're adopting it is not for a practical benefit, just because the distros did.

I run devops though for a small business and we've avoided the issue entirely using runit for our software.

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