[systemd-devel] Antw: Re: [EXT] Re: Run "ipmitool power cycle" after lib/systemd/system-shutdown scripts

[Ulrich Windl]

>>> Etienne Champetier <champetier.etienne at gmail.com> schrieb am 10.02.2022 um
12:47 in Nachricht
<CAOdf3grZ2wUOkJ8Pzu-EM=+ZCKY4b6XK9dyZoh=QpX5HgHJfxA at mail.gmail.com>:
> Le jeu. 10 févr. 2022 à 11:49, Ulrich Windl
> <Ulrich.Windl at rz.uni-regensburg.de> a écrit :
>>
>> >>> Lennart Poettering <lennart at poettering.net> schrieb am 10.02.2022 um
11:31
>> in
>> Nachricht <YgTpdVFRgL+uQoY9 at gardel-login>:
>> > On Mi, 09.02.22 22:05, Etienne Champetier (champetier.etienne at gmail.com)
>> > wrote:
>> >
>> >> Hello systemd hackers,
>> >>
>> >> After flashing the firmware of some pcie card I need to power cycle
>> >> the server to finish the flashing process.
>> >> For now I have a simple script in lib/systemd/system-shutdown/ running
>> >> "ipmitool power cycle" but I would like to make sure it runs after
>> >> other scripts like fwupd.shutdown or mdadm.shutdown
>> >>
>> >> Is there any way to have systemd cleanly power cycle my server instead
>> >> of rebooting it ?
>> >
>> > What does "power cycle" entail that "reboot" doesnt? i.e. why doesn't
>> > "systemctl reboot" suffice?
>>
>> My guess is that some smart cards with their own firmware and CPu do not
>> reboot unless they are power cycled, so maybe if the firmware upgrade on
the
>> card does not force it to reboot, it my need a power cycle.
>>
>> >
>> > /usr/lib/systemd/system-shutdown/ drop-ins are executed before the OS
>> > transitions back into the initrd — the initrd will then detach the
>> > root fs (i.e. undo what it attached at boot) and actually reboot. This
>> > means if your command turns off the power source you should stick it
>> > in the initrd's shutdown logic, and not into
>> > /usr/lib/systemd/system-shutdown/. If you are using RHEL this means
>> > into dracut. But adding it there is something to better discuss with
>> > the dracut community than here.
>>
>> My guess is that it would be handled best by some special GRUB boot menu 
> entry
>> (like "boot 'power cycle' once).
> 
> This is pretty clean but it means going through "BIOS" init twice
> which can be pretty long on physical servers

Hi!

Of course I have a better solution: Use an external server and just before
restarting send a command to that server that will, after a carefully tuned
delay, will trigger the IPMI power-cycle remotely ;-)
I believe that it's almost impossible to trigger a power cycle through IPMI
while also doing a clean shutdown/reboot, unless the the IPMI features a
delayed execution itself.

Regards,
Ulrich

> 
> Etienne
> 
>> Regards,
>> Ulrich
>>
>> >
>> > Lennart
>> >
>> > --
>> > Lennart Poettering, Berlin