Proxmox support for Windows VM time sync after hibernation / resume?

[JamesA]

Does anyone know if there are any plans for Proxmox to support Windows time sync in the future? Maybe someone from Proxmox team can comment?

Currently if you hibernate the Windows VM, then resume it later the time will be out of sync. From what I understand Proxmox does not update the BIOS of the VM on resume meaning the VM has no idea it was hibernated.

VMware ESXi and Hyper-V both have ways to overcome this using their guest tools. But Proxmox seems limited in the functionality.

The only solution I have found is to shutdown the VM and start it again which updates the correct time as the VM grabs the current date/time from the hypervisor on startup. Not a very ideal solution when you have large applications running which take time to startup and shutdown.

Also this is not a production environment. The VM is hibernated as not always needed to be online all the time. I only need to start the VM sometimes to do testing.

 

[nbevans]

This is a big problem. SSL and OAuth/OIDC rely heavily on essentially accurate time. If the clock skew exceeds several minutes, it can cause all sorts of strange problems that cannot be debugged easily. If the UI of Proxmox offers a suspend/hibernate function, it should absolutely ensure the clock is restored correctly when resumed.

 

[JamesA]

Totally agree with you @nbevans
I never got any reply from Proxmox on this. I ended up ditching Proxmox and setting up Hyper-V which works without any issues!

 

[Kingneutron]

https://github.com/kneutron/ansitest/blob/master/proxmox/proxmox-win10-vm-sync-time.sh

https://github.com/kneutron/ansitest/blob/master/proxmox/proxmox-sync-windows-time-beyond-48hrs.sh

Should work as long as the Qemu guest utils are installed and Win has access to a working NTP server. I have a win10 VM running BOINC that's cpu-limited at the hypervisor to 1.9 and it will time out trying to communicate unless I raise the priority of the Qemu agent to High in the VM.

You might want to look into using a bash wrapper to resume the VM and run the time update, I'm fine with running it manually

https://techblog.jeppson.org/2019/10/proxmox-suspend-resume-scripts/

 

[JamesA]

Tried those scripts before and sometimes they work and sometimes they didn’t. It was hit and miss mostly.

Proxmox should add an option on the VM settings to sync the time of guest with host. VMware has it, Hyper-V has it.. Proxmox is lacking this feature..