Red Hat Enterprise Linux 5 Administration Unleashed

540APPENDIX BCreating Virtual MachinesCAUTIONAll the virsh and xm commands given in this appendix must be executed on the hostOS, not on the guest OS running inside the VM.Development on the virsh utility started after xm, but it is rapidly developing. Its goal isto offer more functionality such as being able to maintain virtual machines from otherprograms such as VMWare instead of just from the Virtualization feature in Linux.Because it is projected that virsh is going to be the preferred utility, this appendixexplains virsh. For a list of equivalent xm commands, refer to the “Managing VMs withthe xm Utility” section at the end of this appendix.The virsh commands can be executed in one of two ways. The virsh command can beexecuted as root from a shell prompt followed by a command and any options for thecommand:virsh It can also be started as an interactive so that just the commands and options need to beused. To start the interactive shell, type the virsh command at a shell prompt as root.The following prompt is then displayed:virsh #For example, the command to list the current domains (domains that are shut down arenot shown) is virsh list. If you are in the interactive shell, the command would just belist.Starting and Stopping the Virtual MachineTo start the VM again after installation or any time the VM is shut down, go to the shellprompt (such as starting a GNOME terminal) and execute the following command as root(where is the unique name you gave the VM when setting it up earlier):xm create -c NOTEAs of the initial release of Red Hat Enterprise Linux 5, the Virtual Machine Managerand the virsh utility do not include the ability to start a VM.The pyGRUB menu is displayed as shown in Figure B.12. Select the OS to boot or let thedefault OS be selected and started.