Aleksandr Burmashev

Yeah, you have Centos shim. Ok, let's use heavy artillery. is your system OL/CENTOS 7 ? 1) check your current shim version I assume it is shim-x64-15-8.el7.x86_64.rpm ? http://mirror.centos.org/centos/7/os/x86_64/Packages/shim-x64-15-8.el7.x86_64.rpm 2)...

and surely `grub2-mkconfig > /boot/efi/EFI/redhat/grub.cfg`

The problem with EFI partition detection is that in some cases device is not in the form of sdXY I can suggest following solution: * try to calculate the boot...

> Boot params are UEFI/Legacy Boot: OFF/Secure Boot: OFF. To be on the same page, is system in UEFI mode or legacy ? To check you can check /sys/firmware/efi presence...

Yeah, forget about grub2-install. It is for legacy. Please, just before the reboot do efibootmgr -v find /boot |grep redhat find /boot |grep centos rpm -qa |grep shim

@metal4lyf So you have centos shim and Oracle grub, that explains the problem. pretty sure if you will do 1) rpm -e shim-x64 ( remove centos shim ) 2) yum...

@metal4lyf if the system is not booting with Oracle shim + Oracle grub2, efibootmgr will save you. Pretty much we anyway should apply a fix on our side for this,...

OK, so what is actually happening in your case: since you have migrated from Centos to Oracle, centos EFI binaries are wiped, and Centos UEFI boot entry will be wiped...

Well, if entry was already present you do not need to recreate it. Do both entries persist after reboot ? if yes, pretty much we ( and you ) will...

Referemcing another issue with similar reason https://github.com/oracle/centos2ol/issues/73