Disk Geometry

[Kevin Kinsey]

Dan Simmonds wrote:

> I have a relatively new installation of FreeBSD 5.3 which I have been 
> running
> as a file server. Recently we had a power outage and when I booted up the
> machine again, instead of a normal boot sequence I was given an 
> "automount" prompt.
>
> I understand that I have to mount a disk slice and fsck my hard drive 
> (I think
> this is right, please correct me if I'm wrong), only its been a while 
> since I sliced
> up my hard drive and I've forgotten what the disk looks like. Is there 
> anyway
> of investigating the disk geometry from this automount prompt? The only
> commands I seem to have available are mount commands.
>
> Thanks,
>
> Dan.


(Hi, Dan ... this probably needs to go over to questions at freebsd.org,
where more experience folks will see it, so I'm redirecting the CC there...)

Ouch!  I hope your disk can recover.  Once you get this grassfire
out, be sure and check your backup strategies....

The *only* command you can enter isn't even really a command,
it's simply the answer to the question "where the heck is /boot?"
which is something the system desperately needs to know.

IIRC (and who knows, it has been a little while since I saw this
one, thank Deity) it gives you a hint or two about what to
do.  The usual boot device is /dev/ad0s1 (for IDE drives) or
/dev/da0s1 (for SCSI) and the filesystem type is normally
ufs (but that could vary, ufs2 for example<?>).

Once you get in, you will want to fsck and attempt to
remount your slices; you probably won't have access to a lot
of normal tools (for at least two reasons I can think of:
one being that some of them are on the /usr partition,
and the other being that $PATH is not set, so even stuff
in /bin and /sbin will *say* "not found", just call 'em by the
full path /sbin/fsck, /sbin/mount, etc.)  If everything fscks
clean, try rebooting again to return to multi-user (normal)
mode.

Good luck.

Kevin Kinsey