Proxmox Virtual Environment (PVE) offers powerful virtualization capabilities but tinkering with PCIe devices can lead to unexpected challenges. If like me, you didn’t realize that messing around with PCIe devices in your Proxmox PVE host would break your VMs, keep reading.

In my case, I added a new NVMe SSD, but this can also happen when removing PCIe devices.

Access the Proxmox PVE host with mouse and keyboard and log in as a privileged user.