xen hypervisor fails to boot following a maintenance update

If the boot loader has been configured with a normal kernel, boot it. Otherwise boot the rescue system. Then edit the boot loader configuration file so it points to the correct xen hypervisor file, and reboot to start the xen hypervisor.

For example in grub, the configuration file is /boot/grub/menu.lst and the entry should look like

kernel /boot/xen-4.0.1_21326_08-0.5.1.gz

Verify the exact version currently installed under /boot, to ensure that the bootloader entry matches it. It is also possible to use the symbolic link /boot/xen.gz instead of the full version name, like so

kernel /boot/xen.gz

This symbolic link should always point to the latest installed version of the xen hypervisor.

If the boot loader used is grub, it is possible to change the filename directly on the boot screen. To do this, follow these instructions

1. If grub is in graphical mode, press escape to get to text mode

2. Navigate to the xen boot option using the cursor keys

3. Press 'e' to edit the entry

4. Navigate to the 'kernel' entry using the cursor keys

5. Press 'e' to edit the 'kernel' entry

6. Change the kernel entry to xen.gz and press enter

7. Press 'b' to boot the xen hypervisor

The system should now boot normally. After booting, /boot/grub/menu.lst should be edited as above, to avoid problems on future boots

SUSE development is aware of the problem with the xen updates and is currently looking into the problem, so that future xen maintenance updates may be installable without such issues.