I have a machine with a broken cd drive. So in order to install linux onto the hard drive I removed it and placed it into another machine which has a working CD drive. All went fine, however, that second machine also has an aditional hard drive, which after the install became listed in /etc/fstab

Now the drive is back in the original machine and it "obviously" can't find LABEL=/extra so it won't boot and drops me into rescue mode. I could fix this (I think) by just getting rid of the "LABEL=/extra" line in /etc/fstab but how do I do that from rescue mode?

Am I going to have to take apart both machines and swap drives again in order to fix this?

vi /etc/fstab
move to the line with the non-existing hdd and press
dd
:wq

Done


Cheers,
Tink

Yes, I'm sorry, I should have been more clear. I did try to edit with vi. The problem is that under rescue mode everything is read only, regardless of the file's permisions. Is there a way to get arround this?

Now that would make for a pretty worthless rescue mode!
I suspect that your problem is in using /etc/fstab instead of just etc/fstab.
On my FC4 rescue cd, I type chroot /mnt/sysimage
Then, I verify that I'm looking at the hard drive fstab and not the one on the cdrom...
cat etc/fstab
vi etc/fstab
press the insert key
make changes
press the escape key
type :wq!
then check your work again with cat etc/fstab