Question

After a kernel update, a RHEL 9 server fails to boot. The console displays a kernel panic with the message: 'VFS: Unable to mount root fs on unknown-block(0,0)'. You boot into the previous working kernel entry from the GRUB menu, and the system starts normally. Comparing /boot, you notice the initramfs file for the new kernel is 0 bytes. What is the most appropriate action to fix booting into the new kernel?

Accepted Answer

Reinstall the kernel package and regenerate the initramfs with 'dracut -f --kver <new-kernel-version>', then update GRUB

Answer

Run 'dracut --force /boot/initramfs-$(uname -r).img $(uname -r)' after booting the new kernel version to regenerate the initramfs

Answer

Edit /etc/fstab to change the root filesystem entry to use the device path instead of the UUID

Answer

Run 'grub2-mkconfig -o /boot/grub2/grub.cfg' to rebuild the boot menu and point it at the working kernel