Microsoft introduced Kernel Soft Reboot (KSR) with Azure Stack HCI, version 21H2 (or later) which is a premium feature available on all Azure Stack HCI integrated systems that allows faster server reboots by bypassing the full reboot BIOS/Firmware initialization. Currently, KSR only applies for updates that do not require a cold firmware/BIOS initialization. KSR is disabled by default, and it is important to note that KSR needs to be disabled for our WAC extensions to work.