PVE 5.4.x with Windows Server 2019 / QEMU Hyper-V Flags?

[marsian]

Hi,
we recently started to deploy Windows Server 2019 systems on a PVE 5.4.x environment, which has not been (obviously) migrated to 6.x yet.

One of the deployments are migrated systems from a previous ESXi environment, and we see that the performance is not at the same level as it was before, even if the hardware of the PVE environment is more recent and powerful than the previous ESXi related was. Mostly we're facing read/write issues with local storage, so the "usual" writethrough/writeback experiments still due to be done.

But while looking for potential additional performance tweaks (recent drivers, all emulated devices set to VirtIO etc.), I also came across a couple of references that recommended to enable several Hyper-V related flags in QEMU for affected Windows systems, to change some behaviours of the Windows System - see the link below:

https://github.com/qemu/qemu/blob/master/docs/hyperv.txt

Are there any recommendations/experiences with these flags + Proxmox and if they should be touched at all?

Thanks!

 

[aaron]

I would upgrade to PVE 6.x. From the release notes of PVE 6.0:

• Added support for more Hyper-V enlightenments improving Windows performance in a virtual machine under Qemu/KVM.

https://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_6.0

Switching to VirtIO drivers will help quite a bit as well. Don't forget to set the OS type to the correct setting as well in the VMs Option panel.

 

[marsian]

Hi aaron, thanks for the hints. Doing the upgrade is on our list, but probably will take a couple of weeks for planning etc.

Are there any options to add the known Hyper-V flags manually per VM, or does make no sense on 5.4.x?