I have upgraded from 32 bit Fedora 28 to 30 using dnf system-upgrade, exactly as found in the Fedora documents. All was OK, up to dnf system-upgrade reboot. The started system has upgraded the packages, with cleanup and verify. After numerous hours, the system has restarted but grub cannot boot and it enters the grub command mode.
Using CD rescue disk, I have verified the hard disk and every partition on it using fdisk an fsck. Not problem encountered. I have verified in /boot/ and I have found vmlinuz and initramfs having the expected endings and a size which looks OK.
But /boot/grub2/grub.cfg is strange and very different from the usual structure.
I have booted from the grub command line using configfile /grub2/grub.cfg.rpmsave and I was able to boot as under Fedora 28. I have tried to generate a tentative grub.cfg using grub2-mkconfig and I have put it in /tmp/ in order to compare it with /boot/grub2/grub.cfg. The result: It is exactly the same.
What can I do in order to make the system running well as Fedora 30 as expected ?
Is it a good idea to run dnf update while running this old kernel 28 ?
Best Answer
I had the same issue. Apparently if your Fedora installation is old enough, then it has the issue. I was upgrading from way early version thru those, then 29, then to 30. After the 30 upgrade, it boots to the
grub>prompt.In the end, I followed advice about running
grub2-installfrom Common F30 bugs @ Fedora ProjectI used an installation disk in troubleshoot/rescue mode to be able to manipulate the
grub.cfg. Steps I did were:cp grub.cfg grub.cfg.newcp grub.cfg.rpmsave grub.cfggrub2-install /dev/{boot drive}(for me,{boot drive}wassda)grub.cfgback in place:cp grub.cfg.new grub.cfggrub2-installjust to get whatever FC30 has instead of FC29dnf update