To start virt-manager session open the Applications menu, then the System Tools menu and select Virtual Machine Manager (virt-manager).

The virt-manager main window appears.

Alternatively, virt-manager can be started remotely using ssh as demonstrated in the following command:

ssh -X 
host's address
[remotehost]# virt-manager

Using ssh to manage virtual machines and hosts is discussed further in Section 17.1, “Remote management with ssh”.