Systemd 219 released | Hacker News Reader

Systemd 219 released

lists.freedesktop.org

21 pointscatern17 comments

          * When the user presses Ctrl-Alt-Del more than 7x within 2s an
          immediate reboot is triggered. This useful if shutdown is
          hung and is unable to complete, to expedite the
          operation. Note that this kind of reboot will still unmount
          all file systems, and hence should not result in fsck being
          run on next reboot.

Well that's wonderful. Sticky Keys for Linux. I'm waiting for them to implement a custom recovery shell triggered by the Contra code.

I very much look forward to this feature, when needed it will be useful.

Right Alt+[sysrq,r,e,i,s,u,b]

... and achieves the same thing

http://en.wikipedia.org/wiki/Magic_SysRq_key

But is glitchy and can be awkward to pull off. No guarantees this wont be as well, but we'll see.

Glitchy? Awkward? How so?

I bet you a nickel that the same situations that would cause SysRq+[S,U,B] to fail to properly sync and mount ro would cause systemd's unwedge-the-world emergency reboot to fail to properly sync and mount ro. Notice that the release note says "[Emergency reboot] should not result in fsck being run on next reboot.".

Key timing is odd sometimes which means sequencing can be out of step.

Silly bet.

I was making the point this is useful and convenient in this situation not that it was magic.

Yes, but it's hard to remember, and it depends on Sysrq being enabled. I think the Ctrl+Alt+Del thing makes sense. Since everyone is adopting Systemd, maybe at least it will be ubiquitous. :P

It does have one advantage: You don't have to press all keys. If you system is just locked up cause it's swapping like crazy, it usually gets usable after the e (terminate all tasks).

well if you don't mind altering the order a bit (syncing to disk before all the apps get SIGTERM or SIGKILL) you can use this mnemonic:

  Raising
  Skinny
  Elephants
  Is
  Utterly
  Boring

That's how I remembered it for years

I always just remembered "busier" backwards. I think it's better, cause it makes more sense to sync after killing.

7x in 2 seconds is ridiculously fast. I'm not even sure I can pull that kind of speed off.

Hold down CTRL and ALT; press DEL 7 times. Much easier that way.

Yeah, doing a simple "sleep 2" and trying to press enter 7 times before it returns, showed me how much I was underestimating my button pressing. It's actually not hard.

The hardware database now being a systemd API rather than a udev one, I guess, shows that the systemd-udev migration is going steadily. Lots of emphasis on exploiting btrfs features and beefing up nspawn.

Soon the Linux from Scratch guide will be:

* Compile kernel

* Compile systemd

* Boot

;)

There actually is a grain of truth to that, and it's already here. The LFS book has a separate edition specifically for systemd, as listed here: http://linuxfromscratch.org/lfs/read.html

In looking the table of contents of both editions, it seems that the only high level differences are in the exchange of sysvinit and systemd. Both serve the same purpose, but the implementation is different. If LFS made a BSD init version, then I would expect a forked edition as well. At first it feels more political than technical, but since the underlying configuration files are going to be vastly different, it makes complete sense. I don't even understand how this could be construed as an argument for either side.

A couple of differences is that the systemd version lists dbus, and the classic version lists eudev and syslogd.

Their reason for adopting eudev had something to do with the problems of automating the extraction of udev from the larger systemd source, iirc.

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