Bug#810608: systemd-sysv: on shutdown, fails to inform users that the system is going down

[Francesco Poli]

Control: tag -1 -moreinfo


On Sun, 10 Jan 2016 13:58:44 +0100 Martin Pitt wrote:

> Control: tag -1 moreinfo
> 
> Hey Francesco,

Hello Martin,
first of all, thanks a lot for your very prompt reply.   :-)

> 
> Francesco Poli (wintermute) [2016-01-10 13:25 +0100]:
> > When the box is being shut down (reboot or halt or poweroff), users
> > are not notified in any way of what is happening.
> 
> "shutdown" (or equivalently "systemctl reboot" and friends) does do
> that via wall, exactly like sysvinit. This works here, and we even
> have automatic test cases to verify this.

Mmmmhh, that's not what I experience (see below), but anyway I was
talking about the "reboot", "halt", and "poweroff" commands (actually,
symlinks that define special ways to invoke systemctl).

> 
> This doesn't work very well with the "reboot" command as this does not
> take a "delay time" argument like shutdown.

I am not sure I understand how the delay time argument is relevant here.

I mean: when the "reboot", "halt", and "poweroff" commands are provided
by package sysvinit-core, they do not take a delay time argument
either, but they send a broadcast message to all logged users to inform
them that the system is going down, as I have previously said.
I have always seen such message and I think it's really useful to
understand why your SSH connection was closed.

On the other hand, when the "reboot", "halt", and "poweroff" commands
are provided by package systemd-sysv, they fail to send such broadcast
message.
Please note that the halt(8) man page shipped by package systemd-sysv
even mentions a --no-wall option to suppress the broadcast message!
Hence, I am under the impression that this broadcast message is
supposed to be sent, but fails to be actually sent due to a bug.

This is the reason why I thought I should report this behavior as a bug.

> Normally, on a system with
> multiple/remote users its polite to do something like "shutdown -r 5"
> so that they have a chance to finish their stuff. But none of this is
> specific to systemd.

Sure, but the immediate commands ("reboot", "halt", and "poweroff")
exist for all the situations where it's reasonable or needed to shut the
system down as soon as possible.
I think that informing users of what's happening should be done in any
case.

> 
> Can you confirm that "shutdown 5" is not showing wall messages for
> you, or is this just a misunderstanding?

Yes, I confirm that issuing

  $ su -
  Password:
  # shutdown 5
  Shutdown scheduled for Sun 2016-01-10 18:54:54 CET, use 'shutdown -c' to cancel.
  # Connection to HOSTNAME closed by remote host.
  Connection to HOSTNAME closed.

or

  $ su -
  Password:
  # shutdown
  Shutdown scheduled for Sun 2016-01-10 19:02:32 CET, use 'shutdown -c' to cancel.
  # exit
  $ echo 'I am a regular user now'
  I am a regular user now
  $ Connection to HOSTNAME closed by remote host.
  Connection to HOSTNAME closed.

failed to show the broadcast message to the users.

Hence, the misbehavior I am experiencing seems to also affect the
"shutdown" command, not only the "poweroff" command.


I hope that this clarifies my bug report.
Thanks for anything you may do in order to fix this bug.

Bye.

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
..................................................... Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE
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