Why is important to install QEMU Guest Tools when using Proxmox

What is the Proxmox QEMU Agent?

Proxmox QEMU agent, also known as qemu-guest-agent, is a tool installed in the guest system that establishes communication between the Proxmox VE host and virtual machines.
It also helps improve monitoring, enhance performance, and execute commands on the guest system.

The Role of the QEMU Guest Agent in Virtualization

The key roles and benefits of the QEMU guest agent include:

Guest System Information

The QEMU agent helps get details of the guest system, including IP address, resource usage, and other critical insights. Such information is valuable for monitoring and managing virtual machines.

Guest System Control

The Proxmox QEMU agent allows the user to execute various commands within the guest system, such as shutting down, restarting, or pausing the VM. This level of control streamlines the management of virtualized environments.

Snapshot Support

The QEMU agent is used to freeze the guest file system during backup or snapshot creation. When the guest agent is active, it invokes guest-fsfreeze-freeze and guest-fsfreeze-thaw to improve consistency. And, when the guest (VM) is resumed, such as after a snapshot, it promptly synchronizes its time with the hypervisor using qemu-guest-agent.

Setting Up Proxmox QEMU Agent in Linux

1. First, you need to install the QEMU guest agent in the virtual machine (VM). You can install the qemu-agent-guest package on Linux using the system’s default tool.

For Debian or Ubuntu, you can use:

# apt install qemu-guest-agent

For RHEL-based systems, you can run:

# dnf install qemu-guest-agent

2. After the installation has finished, start the guest service.

# systemctl start qemu-guest-agent

3. And enable it to start automatically during the boot.

# systemctl enable qemu-guest-agent

4. To configure QEMU Agent in VM Settings, you have to access the Proxmox VE web interface (GUI). Then, navigate to the desired VM’s hardware tab and add a new “Qemu Agent” device to the VM.

With these steps completed, the agent will be successfully installed and activated on the VM.  

Using the Proxmox QEMU Agent

With the QEMU guest agent successfully set up, administrators can leverage its capabilities for seamless virtual machine management.

Monitoring Guest System

In the Proxmox web interface, under the “Monitor” tab of the respective VM, you can view real-time metrics such as CPU usage, memory usage, and network activity.

Executing Commands

Perform various actions on the guest system through the Proxmox web interface or command line. For example:

Test the communication with the guest agent:

# qm agent <vmid> ping

Shutdown VM:

# qm agent <vmid> shutdown 

Display the OS information of the VM:

# qm agent <vmid> get-osinfo