F27 boots to grub> after (failed?) dnf update ?

[linux guy]

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 #.

How do I get my server to boot again ?

Thanks