Il 01/08/20 22:03, Greg Bailey ha scritto: > 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 > I did the downgrade on a fresh install of c8.2 but yum said that all selected packages (grub2,shim...) are already to the lowest version and the downgrade is not possibile, ending with "nothing to do".