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Applies to SUSE Linux Enterprise Server 11 SP4

13 SUSE Linux Virtual Machines

On current SUSE Linux Enterprise systems, Xen is fully integrated into the product. It may be used as VM Host Server or VM Guest.

To change the size of the VNC display, an extra option must be supplied to the Xen boot options.

To change the VNC resolution to 1024x768 using 8MB of memory in SLES11, simply edit the file /boot/grub/menu.lst and add the following line to the end of the kernel line:

xenfb.video="8,1024,768

For SLES10, the same parameter is needed. However it must be added to the extra boot parameters of the configuration.

Tip
Tip: Mouse Synchronization in VNC

During the installation of SUSE Linux Enterprise, it may happen that the mouse in VNC is not in sync with the mouse of your controlling X Server. To get both in sync, it is advisable to let SaX2 create an X configuration before the installation starts.

This can be done by adding the parameter sax2=1 to the Additional Arguments in the Create Virtual Machine wizard.

13.1 Using the Add-On Products Program

The Add-On Products program is available during the SLE operating system installation and after installation at YaST › Software › Add-On Products. It allows you to install additional products that may reside on a separate CD, ISO image file, or installation source.

Because paravirtual machines present removable media, such as a CD inserted in the CD reader, as a non-removable disk device, the Add-On Product program does not recognize inserted CD as valid add-on product media.

To use the Add-On Products program on a paravirtual machine, you must set up the add-on product media as a network installation source or copy the ISO image file to the virtual machine’s file system.

On fully virtual machines, you can use the Add-On Products program to specify add-on product media as a network installation source, an ISO image file, or as a CD inserted in the host’s CD reader.

13.2 Virtual Machine Clock Settings

When booting, virtual machines get their initial clock time from their host. After getting their initial clock time, fully virtual machines manage their time independently from the host. Paravirtual machines manage clock time according to their independent wallclock setting. If the independent wallclock is enabled, the virtual machine manages its time independently and does not synchronize with the host. If the independent wallclock is disabled, the virtual machine periodically synchronizes its time with the host clock.

Note
Note

OES 2 NetWare virtual machines manage clock time independently after booting. They do not synchronize with the host clock time.

If a guest operating system is configured for NTP and the virtual machine's independent wallclock setting is disabled, it will still periodically synchronize its time with the host time. This dual type of configuration can result in time drift between virtual machines that need to be synchronized. To effectively use an external time source, such as NTP, for time synchronization on a virtual machine, the virtual machine's independent wallclock setting must be enabled (set to 1). Otherwise, it will continue to synchronize its time with its host.

Procedure 13.1: Viewing the Independent Wallclock Setting
  1. Log in to the virtual machine’s operating system as root.

  2. In the virtual machine environment, enter

    cat /proc/sys/xen/independent_wallclock
    • 0 means that the virtual machine is getting its time from the host and is not using independent wallclock.

    • 1 means that the virtual machine is using independent wallclock and managing its time independently from the host.

Procedure 13.2: Permanently Changing the Independent Wallclock Setting
  1. Log in to the virtual machine environment as root.

  2. Edit the virtual machine’s /etc/sysctl.conf file.

  3. Add or change the following entry:

    xen.independent_wallclock=1

    Enter 1 to enable or 0 to disable the wallclock setting.

  4. Save the file and reboot the virtual machine operating system.

    While booting, a virtual machine gets its initial clock time from the host. Then, if the wallclock setting is set to 1 in the sysctl.conf file, it manages its clock time independently and does not synchronize with the host clock time.

Procedure 13.3: Temporarily Changing the Independent Wallclock Setting
  1. Log in to the virtual machine environment as root.

  2. Enter the following command:

    echo "1" > /proc/sys/xen/independent_wallclock

    Enter 1 to enable or 0 to disable the wallclock setting.

  3. Add or change the following entry:

    xen.independent_wallclock=1

    Enter 1 to enable or 0 to disable the wallclock setting.

    Although the current status of the independent wallclock changes immediately, its clock time might not be immediately synchronized. The setting persists until the virtual machine reboots. Then, it gets its initial clock time from the host and uses the independent wallclock according to setting specified in the sysctl.conf file.

13.3 Updating a Network Installation Source

The installation of SUSE Linux Enterprise Server 9 is only supported from a network installation source. To have the right device names supported in Xen, you must update the kernel and initrd that are used to install the system. Furthermore, the updated kernel must be available in the installation source. In the following example, the network installation source is found at /srv/ftp. Create this directory manually, if it does not exist already.

  1. Get the latest kernel package for your system from the Novell Customer Center.

  2. Create a directory for executables in your home directory: mkdir -p $HOME/bin

  3. Copy the script create_update_source.sh from http://www.suse.de/~ug/tools/create_update_source.sh to the bin/ directory and make it executable.

    cd $HOME/bin
    wget http://www.suse.de/~ug/tools/create_update_source.sh
    chmod 755 create_update_source.sh
  4. Install the package inst-source-utils. Then, change your working directory to your network installation source.

  5. Run the command $HOME/bin/create_update_source.sh /srv/ftp.

  6. Copy all updated packages to the directory /srv/ftp/updates/suse/<arch>/.

  7. Run the following commands to make all the new packages known to the installation source:

    cd /srv/ftp/updates/suse;
    perl /usr/bin/create_package_descr -x setup/descr/EXTRA_PROV
  8. Create the checksums needed for the installation process with the commands:

    cd /srv/ftp/updates/suse/setup/descr
    for i in *; do echo -n "META SHA1 "; \
    sha1sum $i|awk '{ORS=""; print $1}'; \
    echo -n " "; basename $i; done >> /srv/ftp/updates/content

After this procedure, the packages that are copied to the updates directory are available during the installation. However, they will only be used if they are newer than the packages provided by the installation itself.

Note, that in order to use a new kernel during the installation, you must also create an appropriate installation initrd as it is found in /srv/ftp/boot/.

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