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

[Paul Menzel]

Dear Adam,


First, just a note (for myself), `ipmitool power` is a shortcut for 
`ipmitool chassis power`.


Am 11.02.22 um 10:54 schrieb Adam Nielsen:
>>> After flashing the firmware of some pcie card I need to power cycle
>>> the server to finish the flashing process.
>>
>> Can you please tell us the PCIe device, where a normal system reboot is
>> not enough to reset it, so I can avoid buying it?
> 
> Most remote access cards work like this by design.  You might be
> connected to a remote computer via a web browser, and need to get into
> the BIOS to change some settings.  If you reboot the machine, the last
> thing you want is the card to reset as well, causing your remote
> session to drop out.  By the time the card's firmware has started and
> you reconnect, you've probably missed the prompt to press F2/DEL/etc.

Then these remote management cards should allow to be restarted 
separately. The BMC I had to deal with allow that.

> A lot of server hardware (e.g. SAS controllers) have onboard firmware
> which may or may not restart during a reboot.  This is also by design,
> because the cards can take many minutes for the firmware to boot up, so
> by continuing to run the firmware across a restart they can cut the
> server boot time down by many minutes, which makes a big difference if
> you're running an OS that requires frequent reboots.

Why should the firmware need more than one second? There is no reason 
for that. So, one more point to avoid such a device.

> I think most hardware vendors (at least in the server space) view a
> reboot as a means to apply operating system updates rather than a means
> to actually reset hardware.  This would no doubt be why programs like
> ipmitool have an option to automatically power cycle the machine, for
> the rare cases where you do want the hardware reset as well.

Hmm, that would be very strange. Luckily until now, a normal reboot was 
totally fine in my experience with Dell and Supermicro servers.

> It's only really a problem when you try to use this server hardware in
> consumer machines, which don't really have a means to automatically
> power cycle themselves.  Most servers seem to be configurable, to do
> things like intercept a hardware reset and turn it into a power cycle
> automatically, or have an "always on" mode configured where you just
> tell the OS to shut down and power off, and the server will
> automatically power itself back on a few seconds later, or at the very
> least the server will have one of those remote access controllers that
> you can use to remotely power it back on again after you've done a
> normal shut down + power off.
> 
> So if you don't like the idea of parts of the system continuing to run
> across reboots, just stay clear of hardware designed for enterprise
> servers and you'll likely never encounter it.

Yes, that is why I asked, so I will never buy such crappy hardware. With 
Dell and Supermicro servers, rebooting the system was all I needed. (The 
BMC is not reset, but can be done separately while the server itself is 
still running.)


Kind regards,

Paul