xm is a management tool that communicates with the Xen hypervisor through xend—the Xen daemon. Running
xm commands requires administrative privileges on the system as it uses the privileged communication channel between xend and the Hypervisor.
xm is also designed to perform its functions in an asynchronous way.
xm command will immediately return to the caller, but the actual operation may not be complete. Some of the domain commands may actually take quite a long time to complete. The only way to determine whether the command is successfully completed is to print out the list periodically and check it. The two most fundamental operations that we use
xm for are to create a domain and to list the state ...