Re: s6-rc shutdown timing issue

From: Laurent Bercot <>
Date: Sun, 13 Sep 2015 12:57:15 +0200

On 13/09/2015 09:08, Colin Booth wrote:
> I've been digging into managing a system completely under s6 and I
> can't seem to find the right time to run `s6-rc -da change'. Run it
> before sending s6-svscan the shutdown/reboot/halt commands and can end
> up with a situation where your read/write drive has been set read-only
> before your services have come down.

  This is the right way to proceed:
  * First s6-rc -da change
  * Then s6-svscanctl -t /run/service

  I don't understand the issue you're having: why would your rw filesystem
be set read-only before the services come down ?
  - Your non-root filesystems should be unmounted via the corresponding
"down" scripts of the oneshot services you're using to mount them, so
they will be unmounted in order.
  - Your root filesystem will be remounted read-only in stage 3, i.e.
when everything is down.

  If your dependencies are correct, there should be no problem. What
sequence of events is happening to you ?

> One other question that doesn't really belong here but doesn't need
> its own thread. If I have a oneshot that only does any work on
> shutdown, can I get away with having the required ./up script be
> empty

  Yes, an empty ./up script will work. (Oneshot scripts are interpreted
at compile time by the execlineb parser, which treats an empty script
as "exit 0".)

Received on Sun Sep 13 2015 - 10:57:15 UTC

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