Yesterday, I wrote about getting Debian 11 running on an old Mac Mini.
It wasn’t much of a write-up, as it was very easy.
Since I am running it as a server, I’d like it to reboot automatically if there is a power outage. Well, when the power outage is over and power is restored. It’s behind a UPS, so hopefully that should offer a measure of protection against mains blips anyway.
It appears – thanks, ant! – that a small change to the Mini’s power settings will make this happen:
setpci -s 0:1f.0 0xa4.b=0
(There is a seemingly credible explanation.)
However, it is not just a case of setting it once, but setting it on every (re)boot.
Most of the guides – now dated – suggest putting this in
/etc/rc.local. As this has been / is being deprecated, that didn’t seem like a good idea, so I went for a
systemd approach instead.
I created a .service file:
[Unit] Description=Enable reboot on power restoration [Service] Type=oneshot ExecStart=/usr/bin/setpci -s 0:1f.0 0xa4.b=0 [Install] WantedBy=multi-user.target
I enabled it:
systemctl enable --now rebootonpowerrestoration.service
(The use of the the
--now switch means that, as well as it being enabled for next boot, it is started/run now too.)
Did it work?
Yes. It booted fine once power was re-applied.
When I’d logged in, I checked
systemctl status rebootonpowerrestoration.service
and the log showed that the script had run.