supervision - discussion about system services, daemon supervision, init, runlevel management, and tools such as s6 and runit
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From: "Laurent Bercot" <ska-supervision@skarnet.org>
To: "supervision@list.skarnet.org" <supervision@list.skarnet.org>
Subject: Re: SysV shutdown util
Date: Sat, 11 May 2019 12:56:08 +0000	[thread overview]
Message-ID: <em7c5a1307-22bc-43e5-b61c-a06a1eb0bb30@elzian> (raw)
In-Reply-To: <3137641557573985@myt1-4903e6646a45.qloud-c.yandex.net>

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>>  you need to be able to convey more information to pid 1
>>  than a few signals can.
>such as ?
>what more information than the runlevel (0 or 6, maybe 1 to go
>into single user) does SysV init need to start the system shutdown ?

The time of the shutdown. The "shutdown" command isn't necessarily
instantaneous, it can register a shutdown for a given time.
  You could deal with that by creating another process, which is
equivalent to running a daemon outside pid 1 (and that's exactly
what s6-linux-init-1.0.0.0 does), but if you want to handle it all
in pid 1, you need time management in it and that can't be done
via signals only.


>the Void Linux team just made a shell script out of it that just brings
>down the runit services and runsvdir itself.

  Yeah, that's not difficult. What is difficult is implementing the
legacy features of other inits.

--
  Laurent

  reply	other threads:[~2019-05-11 12:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-09  7:10 ipc in process #1 Jeff
2019-05-10 17:57 ` Laurent Bercot
2019-05-11 11:26   ` SysV shutdown util Jeff
2019-05-11 12:56     ` Laurent Bercot [this message]
2019-05-11 12:38   ` emergency IPC with SysV message queues Jeff
2019-05-11 13:34     ` Laurent Bercot
2019-05-16 15:15       ` Jeff
2019-05-16 21:25         ` Laurent Bercot
2019-05-16 21:54           ` Oliver Schad
2019-05-19 17:54           ` Jeff
     [not found]             ` <CALZWFRJws+eDthy8MCFj4PiVdRdRpM+afda6QAbEtYA4NT8ESQ@mail.gmail.com>
2019-05-19 19:59               ` Fwd: " Cameron Nemo
2019-05-19 20:26             ` Jeff
2019-05-19 18:38           ` Bob

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