virstat

virstat is a command-line utility used for monitoring and collecting statistics from virtual machines. It is part of the libvirt virtualization management toolkit and provides a way to access performance data for guests running under hypervisors such as KVM, Xen, and VMware. The tool allows users to view real-time information about CPU usage, memory consumption, disk I/O, and network traffic for individual virtual machines or all active guests on a system.

The output of virstat can be displayed in various formats, including human-readable tables and machine-readable formats suitable for scripting and integration with other monitoring systems. Users can specify which statistics to collect and for which virtual machines, offering flexibility in monitoring needs. For instance, one might use virstat to track the resource utilization of a specific server VM to identify potential performance bottlenecks or to gauge the overall load on the virtualization host.

Common use cases for virstat include performance analysis, capacity planning, and troubleshooting. By regularly collecting and analyzing the data provided by virstat, system administrators can gain insights into the behavior of their virtualized environments, optimize resource allocation, and ensure the smooth operation of their virtual machines. The tool is typically invoked from a terminal, with arguments specifying the target virtual machine and the desired statistics.