[CentOS] 8.2.2004 Latest yum update renders machine unbootable

Fri Jul 31 10:35:48 UTC 2020
Alan McRae <amcrae at island42.net>

I am running an Intel x64 machine using UEFI to boot an SSD.

Installing the latest yum update which includes grub2 and kernel 
4.18.0-193.14.2.el8_2.x86_64 renders the machine unbootable, blank 
screen where grub should be, no error messages, just hangs.

After some hours I managed to modify another bootable partition 
(containing older software) and boot it from there.

After that, I  found out it is a known problem.

The main point of this message is to make people aware of the problem 
and suggest admins don't run 'yum update' until they understand the 
problem and have a fix at hand.

See 'UEFI boot blank screen post update' for a solution and directions 
to the redhat article.