4.1 VM Server

Basic instructions for setting up VM Server are found in Section 3.1.2, Setting up the Xen VM Server. This document contains additional information to help you set up, run, and troubleshoot Xen VM Server.

4.1.1 Obtaining VM Server Software

Xen VM Server software packages are included with SUSE® Linux Enterprise Server 10. The pattern containing this set of packages is named Xen Virtualization. Updates are obtained through YaST Online Update.

4.1.2 Module edd Error Message During Installation

When the kernel-xen package is installed, you can ignore messages stating Cannot determine dependencies of module edd. The message might be repeated two or three times during installation. (179409)

4.1.3 Installing VM Server Software

If you did not install the VM Server software during the initial server installation, make sure to install it using the YaST > System > Virtual Machine Management (Xen) module only. Do not use other installation methods, such as YaST > Software > Software Management because they do not perform the automatic configuration required to correctly run VM Server.

4.1.4 Setting up the VM Server

Basic instructions for installing software and setting up the VM Server are in Section 3.1.2, Setting up the Xen VM Server.

4.1.5 Hardware Support Issues

Some computer hardware is not supported by the Xen hypervisor or domain 0 kernel.

  • Devices on the ISA or PCMCIA bus tend not to work.
  • ISA DMA is not supported by Xen.
  • ACPI support in Xen is improving, but might not be up-to-date with respect to Linux.
  • Some large-memory machines might not boot with ACPI enabled.

4.1.6 Power Management Features

Power management features, such as the suspend-to-disk feature, are not supported and should be disabled on the VM Server and all VMs.

4.1.7 Verifying that Packages are Installed and Running

There are a few methods you can use to verify that theVM Server is running. Each method requires you to access the command line interface or terminal and log in as the root user.

  • Enter rpm -qa | grep xen and verify that the Xen VM Server packages are installed.
  • Enter xm list. The command should display Xen VM Server (as Domain-0) and its properties.
  • Enter uname -r and verify that the kernel version includes the word xen.

4.1.8 Checking the GRUB Boot Loader

When the Xen software packages are installed, the GRUB boot loader is automatically updated to present Xen VM Server as a boot option. The GRUB boot loader configuration file is usually saved to /boot/grub/menu.lst.

You can compare your GRUB boot loader configuration file with the examples below to confirm that it was updated to correctly boot Xen VM Server. The first example shows a typical GRUB boot loader file updated to load Xen VM Server software. The second example shows a GRUB boot loader file that loads the Xen VM Server PAE-enabled kernel, which allows 32-bit computers to access memory over 3 GB.

Sample GRUB Boot Loader File (Typical)

title XEN
 root (hd0,5)
 kernel /boot/xen.gz hyper_parameters
 module /boot/vmlinuz-xen kernel_parameters
 module /boot/initrd-xen

Sample GRUB Boot Loader File (PAE)

title XEN
 root (hd0,5)
 kernel /boot/xen-pae.gz hyper_parameters
 module /boot/vmlinuz-xenpae kernel_parameters
 module /boot/initrd-xenpae

The title line specifies the name of the GRUB module. Do not change this line because YaST looks for the word XEN to verify that packages are installed.

The root line specifies which partition holds the boot partition and /boot directory. Replace (hd0,5) with the correct partition. For example, if the drive designated as hda1 holds the /boot directory, the entry would be (hd0,0).

The kernel line specifies the directory and filename of the hypervisor software. Replace hyper_parameters with the parameters to pass to the hypervisor. A common parameter is dom0_mem=amount_of_memory, which specifies how much memory to allocate to Xen VM Server. The amount of memory is specified in KB, or you can specify the units, for example 128M. If the amount is not specified, Xen VM Server takes the maximum possible memory for its operations. For more information about hypervisor parameters, see the XenSource Web Site.

The first module line specifies the directory and filename of the Linux kernel to load. Replace kernel_parameters with the parameters to pass to the kernel. These parameters are the same parameters as those that can be passed to a standard Linux kernel on physical computer hardware.

The second module line specifies the directory and filename of the RAM disk used to boot Xen VM Server.

4.1.9 VM Server Boots in Text Mode

If selecting the Xen option from the GRUB boot loader menu loads the VM server in text mode, the graphics card is probably not configured correctly. To properly configure the graphics card so you can switch to graphical mode, complete the following steps:

  1. When the computer boots and loads the GRUB boot loader menu, select the option that includes the word xen.

    The computer boots and displays a command prompt.

  2. At the command prompt, enter init 3 to make sure you are in text mode.

  3. Enter sax2 to run the sax graphical configuration module.

  4. Configure the GUI as desired.

  5. Enter init 5 to switch to GUI mode.