On 7/31/20 6:35 AM, Alan McRae via CentOS wrote: > 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. > > ... > 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. I posted, on 7/30, to CentOS-devel the following after my similar experience (booting an mSATA SSD on my M6700, with two 2.5 SATA drives (a 1TB and a 2TB), and the mSATA is not /dev/sda on this hardware, FWIW): "Moral of the story? Have the install DVD on a USB stick and available to boot into rescue mode, know how to boot rescue mode (from the installer boot menu select 'troubleshooting....' then 'rescue....' and option 1 once the menu shows), know how to activate network interfaces in text mode (either nmcli or nmtui works fine for this), and know a few basic dnf commands. And have an alternate means of doing basic web searches available; my android phone this morning was used for that....." I was able to recover with the install DVD on a USB stick and using rescue mode on a laptop with only WiFi (nmtui does a great job for this sort of thing, booted into rescue mode and chrooted onto /mnt/sysimage).