Changes

Xen hardware virtual machine (HVM) provides support for the virtualization of unmodified guest operating systems. Where ever possible it is better to run paravirtualized guests because HVM domainU guests run slightly slower than paravirtualized domainU guests and require that the host system contain a processor type with build in virtualization support. That said, if you need to virtualize an operating system which has not, or cannot be modified to run as a paravirtualized Xen guest (such as Microsoft Windows) then HVM virtualization is the only a good solution.

In order to install a fully virtualized Xen guest some from form of disk storage is needed to contain the installed operating system. This can take the form of a physical disk (such as /dev/sdb) or a disk image file. A suitable disk image file can be created using the ''dd'' command. For example:

dd if=/dev/zero of=XenGuest1xenguest.img bs=1024k seek=6144 count=0

In addition, suitable installation media (such as a DVD or ISO image) will be required from which to install the guest operating system onto the disk image or disk drive.

The example HVM guest configuration file provided wtih with Xen is as follows:

The Firstly, the domainU system needs to be given a suitable name. The ''name = '' filed field should, therefore, be changed accordingly. For example:

disk = [ 'file:/home/xen/XenGuestxenguest.img,hda,w', 'phy:/dev/cdrom,hdc:cdrom,r' ]

The above examples assume that you will be installing the guest operating system from a CD or DVD drive. It is also possible to perform the installation from an ISO image residing on the filesystem of the host. For example:

Both SDL and VNC work well in terms of displaying a graphical console, although VNC has some distinct advantages over SDL. Firstly, VNC provides greater flexibility than SDL in terms of remote access to the domainU graphical console. With VNC it is possible to connect to the graphical console from other systems, either on the local network or even over the internet. Secondly, when you close a VNC viewer window the guest domain continues to run and ytou can allowing you to simply reconnect to carry on where you left off. Closing an SDL window , however, immediately terminates the guest domainU system resulting in possible data loss.

Finally, the boot search sequence needs to be defined. Since we have to install the operating system before we canboot can boot from the hard disk drive we need to place the CDROM/DVD first in the boor order:

The guest system can now be started using the ''xm create'' commandscommandm for example:

All being well the domainU guest will start with output ion to the Xen text console similar to the following:

If SDL was chosen for the graphical console then the console should appear when the guest starts up. If, on the other hand, VNC was selected and the HVM domainU was not configured to automatically start ''vncviewer'' it is now necessary to connect manually. By default the VNC port is 5900 + the ID of the domain to which you wish to connect (which can be obtained using the ''xm list'' command). For example, to connect to domain ID 10:

Once the installation of the guest operating system has completed be sure to reverse the boot order in the configuration file if you no longer wish to have the CD/DVD drive first in the boot order: