A CentOS 8 virtual server does not boot after an operating system upgrade (with yum update).
Refer to the CentOS Linux Templates page to find more details about the CentOS 8 specific issues/limits.
OnApp < 6.3
CentOS Linux 8.* x64 templates
KVM compute resources
The issue has been fixed for version 6.3 and up and the fix is backported to version 6.0 patch 11.
- Reboot the virtual server in recovery mode.
- Locate the primary VS's vDisk. Normally, it is
/dev/vdain recovery on KVM compute resources. Refer to the Recovery Console page.
If the primary VS disk is recognized as a
/dev/vda, prepare the chroot environment:
#mount /dev/vda1 /mnt && mount --bind /proc /mnt/proc/ && mount --bind /dev /mnt/dev&& mount --bind /sys /mnt/sys && chroot /mnt /bin/bash -lCODE
Change the bootloader option and regenerate the config file:
#sed -i 's/GRUB_ENABLE_BLSCFG.*/GRUB_ENABLE_BLSCFG=false/' /etc/default/grub #grub2-mkconfig -o /boot/grub2/grub.cfgCODE
Exit the chroot environment and reboot the virtual server in normal mode.
#exit #cd / && umount /mnt/proc && umount /mnt/dev && umount /mnt/sys && umount /mntCODE
By default, CentOS 8 comes with a new boot scheme (Boot Loader Specification) that is not supported by the OnApp GRUB boot image:
The upgrade overwrites the bootloader option and config files to support the BLS and it requires disabling it and regenerate the bootloader's main config file.