Comment 24 for bug 1678187

Did you upgrade from older release or are the files generated when you were using 20.04? Can you provide any logs concerning the issue? Do the extra initrd.img* files match /boot/initrd.img-*.old-dkms, see https://bugs.launchpad.net/ubuntu/+source/dkms/+bug/1515513 ? Or do you still have the respective kernels (vmlinuz-* etc.) there, too?

It seems that my modified generate_initramfs function has not been applied in /usr/sbin/update-initramfs in 20.04, so you can not remove a kernel successfully. The modified version should do better job not leaving extra files around IIRC. Anyway, it should be possible with my linux-purge utility (https://launchpad.net/linux-purge).