I ran DNF update via ssh on my x86_64 FC27 server the other day. For some
reason it didn't finish and when I rebooted it, it boots to a grub
prompt.
"Minimal BASH-like line editing..." grub>
So...
grub> set root=(lvm/fedora/root)
grub> linuxefi (hd0,gpt2)/linuz-4.14.13-300.
fc27.x86_64
grub>initrdefi (hd0,gpt2)/initramfs-4.14.13-
300.fc27.x86_64.img
grub>boot
This gives me a switch root error and stops at the emergency mode prompt #.