Since virtual machines created with KVM/QEMU are not simple containers but quite isolated from the hosts environment, QEMU offers a companion service called
qemu-guest-agent for Linux guests. qemu-guest-agent acts as an interface between the VMs and the host system.
Some features like passing ACPI information for a clean guest shutdown are pretty well-known. However, did you know that you can even send commands to your VMs directly from your Proxmox host system?
Proxmox Virtual Environment uses KVM/QEMU as virtualization technology. Since calling the qemu-guest-agent interface is not very intuitive by itself, Proxmox provides the qm guest command which acts like a bridge between the host system and the VMs.Read More “Using qemu-guest-agent as interface between VMs and Proxmox host systems”