How to Fix a VPS That Does Not Boot After a Kernel Update

Issue

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

Environment

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 guest’s packages:
   • Update CentOS 6.x with:

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

   • Update Debian 9.x with:

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

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