Virtual Servers Do Not Boot after Kernel Upgrade on Xen

Issue

Upgrading kernel(s) inside Linux guests to the following versions will break them. Updated guest(s) will not ever boot and will crash on startup.

Environment

XEN compute resources
CentOS 6.x kernel version >= 2.6.32-754.2.1.el6.x86_64
Debian 9.x kernel version >= 4.9.0-7-amd64

Resolution

The issue can be fixed in one of the following ways:

1. Skip the recent kernel while updating the guest's packages:
   • Update CentOS 6.x:

   # yum update --exclude=kernel*2.6.32-754.2.1*

   CODE

   • Update Debian 9.x:
   

   # apt-mark hold linux-image-amd64 linux-headers-amd64
   
   # apt-get update
   
   # apt-get dist-upgrade

   CODE
2. After the kernel was updated, add the following kernel options to the GRUB boot loader configuration file:
   • For CentOS 6.x, add the eagerfpu=off option to the edit /boot/grub/grub.conf file
   • For Debian 9.x, add the elevator=noop and pti=off options to the edit /boot/grub/menu.lst file.