Xen Monitoring Tools and Techniques
So far in this book we have focused primarily on the creation of Xen guest domains (domainU). By this stage it is safe to assume that you now have one or more domainU systems up and running on your server or desktop. Given this assumption, this chapter of Xen Virtualization Essentials will be dedicated to providing an overview of the tools and techniques that may be employed to monitor a Xen based environment.
Why Monitor a Xen Environment?
It is important to keep in mind that Xen is an enterprise level environment capable of supporting complex virtualization configurations. As with any complex system it would be naive to assume that the system will run without the occasional performance issues or problem. Deploying Xen virtualization therefore requires an understanding of the tools and techniques necessary to monitor the running environment, identify performance issues and track down problems.
Obtaining Xen Configuration and System Information
Perhaps the most basic step in monitoring a Xen system or isolating a problem is to get a high level overview of the environment and configuration. This information will be of particular importance when requesting help from a vendor or forum. A good way to obtain this information is to use the xm info command. For example, the following example shows output from xm info on a CentOS 5 system:
