I had exactly the same problem. I'm running 18.10, grub2-common 2.02+dfsg1-5ubuntu8
If I go to root from the recovery menu, my root disk is already mounted, and umount says it is busy, so I can't fsck from there either.
I had exactly the same problem. I'm running 18.10, grub2-common 2.02+dfsg1-5ubuntu8
If I go to root from the recovery menu, my root disk is already mounted, and umount says it is busy, so I can't fsck from there either.