Two posts in one day. I think there are pigs flying by my windows. After running the updates on my freshly installed 10.10 server VM XenServer was no longer able to parse the grub file. The message was strangely familiar to a previous problem of the lack of support for Grub2.
Being that 10.10 already had Grub2 I knew that could not be the issue. A quick Google search found another person who encountered this same issue. It seems XenServer cannot parse the “Previous versions” submenu in the grub file that allows you to boot the old kernels. Using xe-edit-bootloader to remove this section fixes the issue. Once it is up you can remove the old kernels. Specifics can be found at the article I used. http://thetechshop.org/showthread.php?518-Citrix-Xen-Server-5.6-VMs-wont-start-after-Xen-Server-Reboot
