I deleted the second virtual disk image from my virtual machine’s SATA Controller thinking I could boot and then delete the mount line from /etc/fstab. Wrong! I found the suggestion here worked for me. The system was already in single user mode because of the missing /dev/ada1p1. So I just needed to run these commands to use vi to delete the offending line (dd) and then restart.
# mount -u / # /rescue/vi /etc/fstab # mount -a # shutdown -r now
