OCI: Missing /boot/loader/entries After Upgrade

Applies To:

Oracle Cloud Infrastructure - Version N/A and later 

Oracle Linux 8 and above 

Linux x86-64 

Symptoms:

Unable to set the default kernel with grubby 

# grubby --set-default  /boot/vmlinuz-5.15.0-105.125.6.2.1.el8uek.x86_64             
The param /boot/vmlinuz-5.15.0-105.125.6.2.1.el8uek.x86_64 is incorrect 

Cause:

The system has been upgraded from Oracle Linux 7 to Oracle Linux 8 but the system does not reflect the correct files under "/boot/loader/entries" directory or the directory is empty. 

# ls /boot/loader/entries 
# 

Solution:

1) Add the below entry into /etc/default/grub file if not already there 

GRUB_ENABLE_BLSCFG=true 

2) Generate the /boot/loader/entries for the currently booted kernel