I have tried both rpm and yum to update the kernel. I have tried a baseline image with no changes to sysctl.conf.
/ is 13% full and /boot is 4% full. The boot proceeds until about the last several lines of text, usually hangs on "Started Virtualization daemon".
I have verified I am using the correct versions for the OS. I have 7.6 workstation. I have tried to update to 957.27.2 and 957.10.1.
I am able to boot into the old kernel and the recovery kernel.