Part II Managing Virtual Machines with libvirt Edit source

The communication between the virtualization solutions (KVM, Xen, LXC) and the libvirt API is managed by the daemon libvirtd. It needs to run on the VM Host Server. libvirt client applications such as virt-manager, possibly running on a remote machine, communicate with libvirtd running on the VM Hos…

A VM Guest consists of an image containing an operating system and data files and a configuration file describing the VM Guest's virtual hardware resources. VM Guests are hosted on and controlled by the VM Host Server. This section provides generalized instructions for installing a VM Guest.

Most management tasks, such as starting or stopping a VM Guest, can either be done using the graphical application Virtual Machine Manager or on the command line using virsh. Connecting to the graphical console via VNC is only possible from a graphical user interface.

Managing several VM Host Servers, each hosting multiple VM Guests, quickly becomes difficult. One benefit of libvirt is the ability to connect to several VM Host Servers at once, providing a single interface to manage all VM Guests and to connect to their graphical console.

When managing a VM Guest on the VM Host Server itself, you can access the complete file system of the VM Host Server to attach or create virtual hard disks or to attach existing images to the VM Guest. However, this is not possible when managing VM Guests from a remote host. For this reason, libvirt…

This chapter introduces common networking configurations supported by libvirt. It does not depend on the hypervisor used. It is valid for all hypervisors supported by libvirt, such as KVM or Xen. These setups can be achieved using both the graphical interface of Virtual Machine Manager and the command line tool virsh.

Virtual Machine Manager's Details view offers in-depth information about the VM Guest's complete configuration and hardware equipment. Using this view, you can also change the guest configuration or add and modify virtual hardware. To access this view, open the guest's console in Virtual Machine Manager and either choose View › Details from the menu, or click Show virtual hardware details in the toolbar.

You can use virsh to configure virtual machines (VM) on the command line as an alternative to using the Virtual Machine Manager. With virsh, you can control the state of a VM, edit the configuration of a VM or even migrate a VM to another host. The following sections describe how to manage VMs by using virsh.