mounting filesystem error

I get error that I have to rund fsck manually on my filesystem, but when I go to run fsck on filesystem ad1s1e I get an error that says can't open device not configured so fsck won't rund on that filesystem. I am only booting up in single user mode. I noticed when I look in the fstab file the ad1s1e filesystem was not in order like the other filesystem. How can I fix this error. How can you edit or change the fstab file when it is read-only. This server ahs been running fine and all of of a sudden the filesystem won't mount. This is the home directories that won't mount. Help!!!!!!

mount -u /

will remount the root system rw so that you can edit you /etc/fstab although I fail to see what that has to do with you fsck problem.

what version of *BSD are we talking about and what was the command you used to fsck.