At 01:03 PM 8/1/2020, you wrote: >On 8/1/20 6:56 AM, david wrote: >>At 02:54 AM 8/1/2020, Alessandro Baggi wrote: >>>Hi Johnny, >>>thank you very much for clarification. >>> >>>You said that in the centos infrastructure only one server got the problem. >>>What are the conditions that permit the breakage? There is a particular >>>configuration (hw/sw) case that match always the problem or it is random? >>> >>>Thank you >> >>I have two servers running Centos 7 on apple >>hardware (one mac-mini and one mac >>server). They both failed to reboot a few >>days ago. So perhaps whatever anti-boot bug >>hit Centos 8, also hit Centos 7. I can't tell >>what version got updated since the system >>simply fails to boot. I don't even get a grub >>screen. I'll have to rebuild the systems from scratch. >> > >You should be able to boot off of installation >media into rescue mode, and downgrade the grub2* and/or shim* RPMs. > >-Greg This is a good idea, if I knew how to "downgrade...". But in any event, I had decided to rebuild from scratch, which of course failed as soon as I did an yum update. So, I'm installing 7.8.2003 with no updates until I see the "all clear -- updates will no longer make your system unbootable" message from the Centos team. In my many years of blindly updating my installations, starting from the free Redhat distributions, through Whitehat and onto Centos, this is the first disaster, and luckily, it didn't hit all my systems. Let's hope there aren't many more. David