When proxmox is managed by ups...

[oknet]

Succesfully installed NUT , tests are ok but...

Note: Server bios is setup to power ON when mains came back.

Loss of mains: UPS goes on battery.
When NUT receives a LowBattery signal from UPS, it starts the server shutdown.......server goes off but is still powered by UPS remaining battery capability.
Mains comes back before UPS batteries die at all.
For server power management (power supply) mains HAS never been lost , so server won't start unless the power button will be MANUALLY pushed !!
That's a great issue for unattended installations.
Any workaround ?

 

[HgTxRx]

Depending on your machines, you can use Wake On Lan (WOL) to either manually restart your server or write a script to automate it.
in my environment - I use my router (pfsense) to send the WOL packets and it works well.

 

[oknet]

well... WOL seems to be the solution...
Thanks

 

[VictorSTS]

On dual PSU systems, get one PSU directly connected to mains and configure the BIOS to start the server if power is lost. Maybe the system will start when power is restored, haven't tested. Besides WOL, if the server has some kind of out of band management like IPMI, ILo, iDrac, etc, you could use it to power up the server again.

 

[rungekutta]

I can’t remember the details and don’t have it in front of me but I thought Nut could be configured to continue with shutdown of the UPS (and therefore cut power to the server) once beyond a point of “no return” and even if power then comes back again? In order to avoid exactly this problem. Have you checked the Nut documentation and the state diagram and made sure you shut down the server at the right time?

Edit: in this scenario the UPS would obviously only remain off for a number of seconds (configurable) before switching back on again. Pretty sure I tested this entire flow with my APC SmartUPS and found it to be working.

 

[oknet]

Ilo or Idrac are good options I've not considered... thanks

Question, if NUT (or me manually) issues a "shutdown -h now" to proxmox server, does it attempt a graceful stop of running VMs firts ?

 

[leesteken]

Question, if NUT (or me manually) issues a "shutdown -h now" to proxmox server, does it attempt a graceful stop of running VMs firts ?

Yes for shutdown -h now (and you can test this really easily by doing it and checking the logs afterwards or the host console during).

 

[VictorSTS]

Make sure that your VMs honor ACPI shutdown signals or preferably enable and install QEMU Agent. If VM does not shutdown itself when Proxmox asks it to do so, after the default timeout of 180 seconds the VM will be killed with a kill -9. That's not only bad for the safety of the VM, but will extend the time needed for the server to power off.