After trying several paths, some suggested on this list, here's my results. 1) Fixing a unbootable system wasn't practical in my case. Fortunately, all my systems can be rebuilt from scratch. 2) When I was lucky enough to catch an updated system before reboot, backing out the defective updates wasn't possible. Yum said there were no prior versions. 3) The most reliable method I found for Centos 7 was: - Re=install from scratch (luckily, my data files were safe and restorable) - Before running any updates, apply the fix suggested by Redhat and exclude updates to grub2, shim and mokutil. - Without the above 'exclude', the system became unbootable after a yum update even though the corrected versions of shim should have been loaded. The system I'm dealing with is Centos 7. I can easily rebuild it from scratch and test stuff without losing crucial data, if it would helpful. 4) I haven't experimented yet with centos 8 because the hardware is remote and requires me to get a friend involved to help. My local hardware is not supported by Centos 8, so it will remain on Centos 7 until I replace the hardware or switch to a different Linux. David
Le 03/08/2020 ? 19:24, david a ?crit?:> After trying several paths, some suggested on this list, here's my results.Hi, Just back from a hiking trip. One of my clients sent me a message that his CentOS server refuses to boot. So tomorrow I have to drive there to figure out what's going on. I guess there's a high probability it's the issue discussed in this thread. Simple question: besides a tsunami of mailing list and forum messages, is there some to-the-point reliable information about this mess ? As well as some to-the-point reliable information about how to fix it ? Thanks, Niki -- Microlinux - Solutions informatiques durables 7, place de l'?glise - 30730 Montpezat Site : https://www.microlinux.fr Blog : https://blog.microlinux.fr Mail : info at microlinux.fr T?l. : 04 66 63 10 32 Mob. : 06 51 80 12 12
Hi all, I had the same problem with my UEFI bios machine and I fixed it so for Centos 7: 1) Boot from an rescue linux usb 2) When the rescue system is running: ??? 2.1) #chroot /mnt/sysimage 3) Config network: ??? 3.1) # ip addr add X.X.X.X/X dev X ??? 3.2) # ip route add default via X.X.X.X??? <--- default router 4) And finally: ??? #yum downgrade shim\* grub2\* mokutil ??? #exit ??? #reboot I hope you can fix it with these steps. El 4/8/20 a las 0:56, Nicolas Kovacs escribi?:> Le 03/08/2020 ? 19:24, david a ?crit?: >> After trying several paths, some suggested on this list, here's my results. > Hi, > > Just back from a hiking trip. One of my clients sent me a message that his > CentOS server refuses to boot. So tomorrow I have to drive there to figure out > what's going on. I guess there's a high probability it's the issue discussed in > this thread. > > Simple question: besides a tsunami of mailing list and forum messages, is there > some to-the-point reliable information about this mess ? As well as some > to-the-point reliable information about how to fix it ? > > Thanks, > > Niki >--