Need to boot from CD and delete a file on the hard drive

Charles Howse chowse at
Tue Oct 25 11:33:56 PDT 2005

> Hello All --
> I changed a configuration file and now I can no longer boot from my hard drive
> (but I can still 
>  boot from the CD). I would like to boot from the CD and undo my change to the
> configuration 
> file -- but when I boot from the CD it automatically launches the install
> program. Is there a way
>  to boot from the boot CD and get a shell and make a change to a file on the
> hard drive? (I got
> an "emergency shell" after booting from the CD -- but I can't figure out how
> to access my hard
> drive filesystem from it.)
> I was trying to set up a serial console using the instructions here:
> html
> I typed the following at the prompt:
> # echo 'console="comconsole"' >> /boot/loader.conf
> then unplugged my regular keyboard and tried to reboot -- but the machine now
> freezes on 
> bootup.
> I now want to boot from a CD and remove the file /boot/loader.conf from the
> hard drive. Then I
> should be able to boot normally again from the hard drive.
> I went into the BIOS and booted from the CD and this put me in the install
> program. I don't 
> want to install everything again -- I just want to boot up from the CD and
> execute the following
> command at the prompt:
> # rm /boot/loader.conf
> After booting from the CD, I found a command in the install program to enter
> an "emergency 
> shell" and accessed this shell by hitting ALT-F4 -- but if I do an "rm"
> command in this 
> emergency shell, it doesn't apply to the filesystem on the hard drive -- it
> applies to the CD. I
> need to delete the file /boot/loader.conf while booting from the CD.
> Is there any way to fix this without installing FreeBSD all over again?

I've never done this...but...
Reboot the computer from the CD,
Look for the message:

Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [kernel] in 9 seconds...

At that point press "any other key".
You should then be able to mount your /boot partition and delete the file,
however, you may have to look around on the CD for the appropriate commands.

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