Path: utzoo!attcan!utgpu!watmath!att!dptg!rutgers!cs.utexas.edu!csd4.milw.wisc.edu!dogie.macc.wisc.edu!uwvax!shorty!thurm
From: thurm@shorty.CS.WISC.EDU (Matthew Thurmaier)
Newsgroups: comp.sys.ibm.pc
Subject: Re: No hard disk recognition---HELP!!
Keywords: Xenix, hard disk, HELP, Fixed Disk Master Boot Record
Message-ID: <8127@spool.cs.wisc.edu>
Date: 9 Aug 89 06:26:31 GMT
References: <451@ntcsd1.UUCP> <9101@thorin.cs.unc.edu>
Sender: news@spool.cs.wisc.edu
Reply-To: thurm@shorty.cs.wisc.edu (Matthew Thurmaier)
Organization: The Computer Classroom - An SCO Authorized Training Center.
Lines: 78


One of the things that we teach in SCO Authorized classes is how to recover
from crashes like this.

There are several things that you may want to try:
1.) If the hardware isn't being seen by anything, then your configuration is
	fouled.  If I remember correctly, this is NOT your case though.

2.) If the system tries to boot off of the hard disk but can't find the magical
	boot program spoken of earlier by 9101@thorin.cs.unc.edu, then you can
	place your N1 floppy in the floppy drive and type "hd(40)/xenix" at the
	boot
	:
	prompt.  This will boot from the floppy, but load xenix from the hard
	disk.

	if it can't find /xenix, try "/xenix.old" and "/usr/sys/conf/xenix-".

3.) If it boots, but can't find a xenix, then you can boot off of N1, and
	press the DELETE key when it asks you if you want to continue.  Something
	that most people don't understand is that there is nothing really magic
	about the installation disk N1.  You still have XENIX running, but you
	have a limited set of commands.  Things like 'ls' aren't there, but
	who needs them when you have "echo *".  'cat' can be replaced with an
	appropriate 'dd' command. So...

	You now have a prompt of " ".  try the following:

	fsck -n /dev/rhd0root

	You may need to proceed the 'fsck' w/ a '/bin/' or '/etc/', it is late
	and I can't remember if you path is set up by then, and if not, where
	fsck is kept.  Anyway, the '-n' says "DON'T MAKE ANY CHANGES".  This
	will prevent fsck from clobering your potentially corrupt but salvagable
	system.  If you are really gutsy, leave of the -n.  But, don't say yes
	to any questions asking you if it's ok to clear an I-NODE of 400 or less.
	400 is actually just a rule I came up with a long time ago.  It works for
	me.

	If the system fsck's, then mount it with:

	mount /dev/hd0root /mnt

	Then copy over your xenix with:

	cp /xenix /mnt/xenix

	Then you may have to brand the /mnt/xenix with your serial number.  Look
	up brand in either (C), (M), or (ADM).  Again, all commands may need a
	"/etc" or "/bin" in front of them.

	At this point, you should have a kernel.

4.) If you boot block is bad on your disk, then you will have to either use
	'dd' to put one there by hand (again, the /boot program is on your N1)
	or use the 'mkfs' command with a prototype file, which precludes you 
	from getting any valuable data off of the root filesystem, since you
	just re-made it.


A word to everyone about this lesson, make yourselves a bootable-rootable
floppy disk with your already-serialized/branded kernel and all of your 
drivers (like cartridge tape [hint hint]) and devices (like /dev/rct0) and
all of your favorite utilities (like vi and a truncated /etc/termcap) while
you have a working system.  You can do this with "mkdev fd".

Good Luck.  I will be in my office most of tomorrow and will be pleased to
answer questions then.


Matthew.
Snail Mail:                                 E Mail:
Matthew J. Thurmaier                ...!{allegra,harvard,seismo}!shorty!matt
The Computer Classroom              matt@shorty.wisc.edu
6701 Seybold Road, Ste. 122
Madison, WI 53719
(608) 271-2171
                                  "why am I ALWAYS going somewhere?" >>-matt-->