diff --git a/pages/instances/reference-content/understanding-qemu-guest-agent.mdx b/pages/instances/reference-content/understanding-qemu-guest-agent.mdx index 0f4b3f1a43..f5c95b6bb6 100644 --- a/pages/instances/reference-content/understanding-qemu-guest-agent.mdx +++ b/pages/instances/reference-content/understanding-qemu-guest-agent.mdx @@ -15,6 +15,28 @@ This page provides essential insights into this mechanism. This documentation page does not apply to Instances running the Microsoft Windows operating system. +## What is the QGA? + +The QEMU Guest Agent (QGA) is a daemon designed to run inside virtual machines, enabling communication between the guest operating system and the QEMU hypervisor. It supports tasks such as system configuration and resource monitoring. + +The QGA source code is publicly available in the [QEMU repository on GitLab](https://gitlab.com/qemu-project/qemu/-/blob/master/docs/interop/qemu-ga.rst). + + + In addition to the QGA, another daemon is preinstalled on recently created Instances: `scaleway-vmagent`. This agent was developed by Scaleway's engineering teams and is used to send metrics about your VM to [Cockpit](/cockpit/) to monitor the status of your Instance. + You can find the source code of the agent on Scaleway's [Launchpad repository](https://launchpad.net/~scaleway/+archive/ubuntu/stable/+packages). + + +## Which tasks are allowed for the QGA? + +Scaleway has intentionally restricted the QGA to the following allowed tasks (configured in `/etc/qemu/qemu-ga.conf`): + +* `guest-file-close` +* `guest-file-open` +* `guest-file-write` +* `guest-ping` + +All other Remote Procedure Calls (RPCs) are disabled to limit the scope of external execution from the QEMU hypervisor. + ## What are the features provided by QGA? Running the QEMU Guest Agent (QGA) on your Instance currently enables the following feature: @@ -23,6 +45,11 @@ Running the QEMU Guest Agent (QGA) on your Instance currently enables the follow Additional features may be added in the future. +## What is the performance impact of running the QGA inside my VM? + +The performance impact of running the QGA is negligible. The agent consumes very little RAM (<5 MB) and CPU (<0.1%), and there is no measurable I/O or network overhead when idle. +The only operation the agent performs is reading from or writing to a file **in the VM** each time a public IP is attached to or detached from the VM. + ## Checking QGA's status Since March 1st, 2024, all Scaleway-provided GNU/Linux and InstantApp images for Instances come with QGA pre-installed and enabled by default.