Following the update of Hyper-V systems to Messaging Gateway (SMG) 10.7, the SMG virtual machine fails to boot with a kernel panic message on the system console.
This issue appears to only affect Hyper-V installations with limited space in the /boot filesystem
This is an unrecoverable failure in the software update process and the system will need to be reinstalled and the latest backup restored or rolled back to the latest virtual machine snapshot. Please see How to perform an OSRestore on Messaging Gateway for details on the OSRestore process.