Install Qemu guest agent for CentOS

This article will guide you through the process of installing the qemu guest agent on your virtual private server. The guest agent is a helper daemon that facilitates communication and command execution between the guest and host for tasks such as snapshotting and backing up. Its main purposes are to ensure proper shutdown of the guest and to freeze the guest file system during backups.

Step 1: Log in using SSH or via the Console

You must be connected via SSH and logged in as a user with sudo or root privileges.

Step 2: Make sure that the qemu-guest-agent package is not already installed on your system. By default, if you selected CentOS as your operating system during signup with CIFNet, it should be pre-installed.

The commands to do are: 

ps axuw | grep qemu
systemctl status qemu-guest-agent

If the package is installed, the command output should appear similar to this. 

root      8335  0.0  0.1  44168  2236 ?        Ss   13:02   0:00 /usr/bin/qemu-ga --method=virtio-serial --path=/dev/virtio-ports/org.qemu.guest_agent.0 --blacklist=guest-file-open,guest-file-close,guest-file-read,guest-file-write,guest-file-seek,guest-file-flush,guest-exec,guest-exec-status -F/etc/qemu-ga/fsfreeze-hook

If the package is running, the output should appear similar to this: 

$ systemctl status qemu-guest-agent
Б≈▐ qemu-guest-agent.service - QEMU Guest Agent
   Loaded: loaded (/usr/lib/systemd/system/qemu-guest-agent.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2023-01-22 13:02:43 CST; 14min ago
 Main PID: 8335 (qemu-ga)
   CGroup: /system.slice/qemu-guest-agent.service
           Б■■Б■─8335 /usr/bin/qemu-ga --method=virtio-serial --path=/dev/virtio-...

If the qemu-guest-agent package is already installed, you can skip the rest. If it is not installed, please proceed with the next steps.

Step 3: Install qemu guest agent

yum install qemu-guest-agent

Step 4: Start qemu guest agent

Please note that the guest agent may not start automatically after installation. You will need to start it manually by using the following command: 

systemctl start qemu-guest-agent

Step 5: Verify

Verify that the qemu quest agent is running 

systemctl status qemu-guest-agent

Conclusion:

Congratulations, you have successfully installed the qemu guest agent on your CentOS virtual machine.