Automatically Starting Guests; Changing Between The Kvm And Xen Hypervisors; Xen To Kvm - Red Hat ENTERPRISE LINUX 5 - VIRTUALIZATION GUIDE Manual

Chapter 31.
Tips and tricks
This chapter contain useful hints and tips to improve virtualization performance, scale and stability.

31.1. Automatically starting guests

This section covers how to make virtualized guests start automatically during the host system's boot
phase.
This example uses virsh to set a guest, TestServer, to automatically start when the host boots.
# virsh autostart TestServer
Domain TestServer marked as autostarted
The guest now automatically starts with the host.
To stop a guest automatically booting use the --disable parameter
# virsh autostart ---disable TestServer
Domain TestServer unmarked as autostarted
The guest no longer automatically starts with the host.

31.2. Changing between the KVM and Xen hypervisors

This section covers changing between the KVM and Xen hypervisors.
Red Hat only supports one active hypervisor at a time.
Migrating virtualized guests between hypervisors
Presently, there is no application for switching Xen-based guests to KVM or KVM-based
guests to Xen. Guests can only be used on the hypervisor type that they were created on.
Warning
This procedure is only available for the Intel 64 or AMD64 version of Red Hat Enterprise
Linux 5.4 or newer. No other configurations or Red Hat Enterprise Linux versions are
supported. KVM is not available in versions earlier than Red Hat Enterprise Linux 5.4.

31.2.1. Xen to KVM

The following procedure covers changing from the Xen hypervisor to the KVM hypervisor. This
procedure assumes the kernel-xen package is installed and enabled.
Install the KVM package
1.
Install the kvm package if you have not already done so.
# yum install kvm
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