No QEMU guest agent configured (even though it's running)

[HOPE IT]

This seems very similar to https://forum.proxmox.com/threads/guest-agent-not-running.74587/ but thought I should start my own thread.

I tried following the directions in https://pve.proxmox.com/wiki/Qemu-guest-agent. According to those "You have to install guest-agent in each VM and then enable it" (my emphasis added). This yellow warning reinforced that I shouldn't enable it until after the agent is installed.


But according to @ielbury in that other thread:

They need to be set before you boot the VM and install the drivers. If you enable either of these after you have installed the drivers, you need to go the device manager and make sure that the devices are there and install the drivers if necessary.

Anyway, here's what I did before reading that thread:

1. I downloaded virtio drivers from https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/virtio-win.iso (version 0.1.229)
2. I installed VirtIO drivers
3. I installed the QEMU guest agent
4. I enabled the guest agent under VM → Options → QEMU Guest Agent
5. I restarted the VM

Get-Service QEMU-GA shows that the service is running on the VM (and I double checked manually in Services) but when I try to ping it from the Proxmox host I get "No QEMU guest agent configured". It also says "No Guest Agent configured" on the Summary tab of the VM.

After reading the above thread about needing to enable guest agent before installing drivers (which seems to go contrary to the instructions and the bright yellow warning when enabling it) I then tried:

1. Uninstalling and reinstalling the VirtIO drivers
2. Restarting the VM again

But still no change. I'm not seeing the VirtIO Serial Driver referenced in the other thread (see screenshot below), even if I show hidden devices. [Although I can see the the QEMU FwCfg Device not starting, as per https://forum.proxmox.com/threads/virtio-drivers-qemu-fwcfg-device-error.121523... I only mention it in case it is somehow related]



Vital statistics are:

• 2 hosts in cluster, each an Intel NUC12WSKi7
• Proxmox VE 7.4.3 on host pve2 (7.3.3 on pve1)
• Windows Server 2022 on guest VM 100

I'd be grateful for any suggestions on what I am doing wrong... Or ideas for what I should I try next to troubleshoot.

 

[cwt]

Did you shutdown the VM or just reboot? To get hardware changes working (adding or removing components) the VM has to be shut down. So you should

- shut down the VM
- add the guest agent
- start the VM
- install the driver (virtio serial)
- install the guest agent (msi for windows)

 

[HOPE IT]

Ahhh, thank you! That also explains the part of my screenshot where QEMU Guest Agent was both "Default (Disabled)" and "Enabled" (in a different colour)... the change had been saved but not yet applied!

If you follow the Best Practices Guide this shouldn't affect you but in case anyone else stumbles into a similar situation and is wondering what order to install the agent software vs enable the agent on the VM, I did some quick testing and as far as I can tell, it doesn't matter. And as @cwt kindly explained, if you do enable the agent hardware after creating the VM, you'll need to shut the VM right down so Proxmox can attach the agent hardware.

Here's how I tested it for anyone who is curious:

• I tested on Proxmox VE 7.4.3 using two Windows Server 2022 VMs
• I created both VMs from scratch. On one I ticked "Qemu Agent" on the System tab while creating the VM, the other I left it unticked (so I could add it later, after installing the agent software)
• All other VM settings were the same (almost entirely left at the defaults)

On first boot, the one with the Qemu agent enabled had an extra PCI Simple Communications Controller in Device Manager:


It also had "Guest Agent not running" rather than "No Guest Agent configured".

I then installed the virtio-win-gt-x64 drivers (all of them). Installing these moved the "Other devices" to "System devices":


I then installed emu-ga-x86_64 on both machines. At this point, the one with Qemu Agent already installed in the VM started reporting its IP address to the PVE node and seemed to be fully functional (although it's Windows so it probably needs a reboot after installing drivers).

I shut them both down from inside the VMs, enabled Options → QEMU Guest Agent on the second machine and started them both up. Once started up, both machines had both VirtIO devices (ballon driver and serial driver) and both machines were reporting back to the PVE nodes correctly.

Conclusion: it probably doesn't matter which order you install the drivers or the agent "hardware", just as long as you do both.