*BSD News Article 20067


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From: burgess@brooks.af.mil (Dave Burgess)
Newsgroups: comp.os.386bsd.announce,comp.answers,news.answers
Subject: comp.os.386bsd.announce Frequently Asked Questions (Part 6 of 9)
Followup-To: comp.os.386bsd.announce
Date: 26 Aug 1993 15:20:16 -0000
Organization: Armstrong Laboratory, Brooks AFB, TX
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Message-ID: <386bsd-faq-6-746378397@brooks.af.mil>
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Posted-By: auto-faq 2.4
Archive-name: 386bsd-faq/part6

Section 6.	(Interaction with MS-DOS)
6.0	Working with DOS and BNR/2 related software.

	This section is designed to cover some of the more common 
	problems that DOS will have when interacting with BNR/2.
	There are other sections of the FAQ that deal with 
	indirectly with this .  Try looking in sections 0, 1, and 2
	to see if something in there (particularly when talking 
	about DOS and *BSD coexisting on a single drive).

	
6.1	Formatting a floppy

	There is a rumor that floppy formatting either is possible or was
	possible at one time.  If you see any software or FTP sites with 
	anything about this, please contact burgess@hrd769.brooks.af.mil
	and I will make sure it gets updated in here.

	
6.2	Sharing the Disk with MS-DOS

	There are a myriad of questions about how to share a disk between
	386bsd and MS-DOS.  They all boils down to one of the <n> following
	questions:

	1)  How can I partition my drive for both MS-DOS and 386bsd?
	2)  I can install using the whole disk, but I can't install when 
	I try to share the drive between 386bsd and MS-DOS.  Why?
	3)  I can use either MS-DOS or 386BSD on my hard drive,
	but shutdown -todos doesn't seem to work.


6.2.1	How can I partition my drive to support both MS-DOS and 386bsd?

	NOTE:  Before attempting to install 386bsd on a computer with an
	active DOS partition, ALWAYS back up your hard drive.  No one on 
	the net, no matter how talented, can help you recover a hosed 
	MS-DOS file system.  If you lose all of your data, it is YOUR
	fault.

	During the install phase, you need to have un-allocated space left
	on your disk drive.  This allows the install program to correctly
	install the 386bsd partition in the partition table and DOS to
	peacefully co-exist with 386bsd.

	If you do not have any space available on your hard drive, you will
	not be able to install both.  Re-fdisk your hard drive and make
	sure you have left un-allocated space in the partition table.  
	This WILL wipe out your DOS partition - Permanently.

	Even though the partition table procedure above may have worked, 
	there are still no guarantees that your system will boot after
	the install.  This problem most often manifests itself as one of
	the endless reboot problems.  You would normally be able to boot
	DOS from the hard disk, but not 386bsd (once that partition is
	marked as active).

	Once the partition table has been correctly defined with both
	DOS and 386bsd, there can still be problem.  One of the most
	common is that the disk drive works in some sort of translation
	mode.  This is particularly common with drives that physically have
	more than 1024 cylinders.  DOS cannot access a drive with more than
	1024 cylinders.  Translation mode will have to be turned off, usually
	by redefining your hard drive in SETUP as one of the user definable
	types.  This change will normally trash your hard drive, or at least
	render your DOS partition unreadable.

	The solution to this problem is to install 386bsd at the end of the
	hard drive.  While DOS cannot use cylinders above 1024, 386bsd has
	no such limitations, once it has booted.  During the boot-up phase,
	some of the newer boot blocks will refer to the BIOS for some
	services.  Specifically, the disk is checked for a bad sector map
	on the last track.  Since the BIOS cannot deal with cylinders
	higher than 1024, your bad sector map will be incorrectly
	identified as 1023 if the number of cylinders is larger than that.
	This problem is being worked on, and I hope to change this section
	with better news later.

	NOTE:  The only people that this problem will effect are those 
	MFM and ESDI users that have drives with more than 1023 tracks.  
	While drives of this type are not the overwhelming majority, 
	neither are they an anomoly.  People are working on it.

	As an example, if your hard disk physically has 8 heads, 16 sectors 
	per track, and 2000 cylinders (128M); you MUST use some sort of disk
	translation in order to use the entire drive.  An obvious geometry
	for this drive (for DOS) would be 16 heads, 16 sectors, and 1000
	cylinders.  Unfortunately, 386bsd operates using the disk drives
	native geometry as reported during the probe phase of boot up.  This
	will probably be 8/16/2000, and will NOT agree with your translated
	disk geometry.  This causes an endless reboot cycle.  If you change
	the geometry so that the drive agrees with the disklabel, your DOS
	partition is toast.

	The best way to operate in this case would be to (for example)
	split the disk in half.  That leaves 64M for DOS, using a 
	geometry of 8 heads, 16 sectors per track, and the first 1000 
	cylinders for DOS.  The second 1000 cylinders could then safely
	be used for 386bsd.  The DOS partition table may even be capable of
	showing this partition as it actually exists.

	Luke Mewburn <zak@rmit.edu.au> has provided the following tutorial on 
	using the pfdisk program and making your 386bsd/NetBSD partitions
	peacefully coexist with DOS:


			Getting NetBSD 0.8 to coexist with DOS.

		    Written 930510 by Luke Mewburn <zak@rmit.edu.au>


	NetBSD can be made to happily co-exist with DOS if its install
	program knows how to modify the partition table. This assumes
	that you have access to a program which enables you to edit the
	partition table of your hard drive (such as Norton Utilities, or
	pfdisk).

	When you partition your hard drive, you will probably have a large
	partition in which you wish to place NetBSD. This has to have the
	partition ID of 165d (or 0xA5). To change this, you can use the
	'Partition Edit' section of Norton's, or you can use pfdisk.
	This document will go into more detail on how to use pfdisk, as it's
	freely available.

	I'll use my personal drive specifications in the following example.
	It is a 1001 cylinder, 15 trk/cyl, 17 sec/trk, 125MB drive. I
	low-level formatted it, and used fdisk on a MS-DOS 5.0 boot disk to
	create a primary partition '1' of 32MB, and an extended partition '2'
	of 93MB.  I formatted the drive with format c: /s to give myself a
	bootstrap for DOS (much faster than floppies :), but this isn't that
	necessary. Now, the next stage...

	Running pfdisk 0 (to access my first (and only :) HD) came up with
	something like:
	
	For help, enter: '?'
	pfdisk>

	At the prompt, enter 'l' to list partitions, giving (in my case),
	something like:

	# Partition table on device: 0
	geometry 1000 15 17 (cyls heads sectors)
	#  ID  First(cyl)  Last(cyl)  Name  # start, length (sectors)
	1   4      0        256       DOS16 # 17, 65518
	2   0    257        999       unkno # 65535, 189465
	3   0      0          0       empty # 0, 0
	4   0      0          0       empty # 0, 0
	active: 0 (none)

	(Note that there is 1 cylinder less - the last one is, I think,
	for the IDE controller to use when auto-mapping dud sectors out.)

	Now, we want to change the type of #2 (the prospective NetBSD
	partition) to 165. You can obtain a list of known IDs by selecting
	'I'. Depending on the version of pfdisk you have, 165 may or may not
	be known. This doesn't matter too much either way. To get the NetBSD
	install program to use the 2nd partition, I would enter:

	pfdisk> 2 165 257 999

	Another 'l' to list partitions would show that the entry for
	partition 2 will either look like one of the following (depending
	on whether pfdisk knows about the 386bsd partition type or not):

	2 165    257        999       unkno # 65535, 189465
	or
	2 165    257        999       386BS # 65535, 189465


	You could set the active partition with 'a 2' if you want NetBSD
	to always boot, but I personally recommend that you obtain a copy
	of OS-BS 1.35 or BOOTEASY to save you the hassle of running fdisk
	or pfdisk every time you wish to swap system types.

	To complete everything off, do 'w' to write out the info (once
	you're sure it's correct! :), and 'q' to quit the program.


	Well, I hope that is useful to someone. Comments can be directed
	to the author (Email: <zak@rmit.edu.au>).


6.2.2	I can install using the whole disk, but I can't install when 
	I try to share the drive between 386bsd and MS-DOS.  Why?

	This is an extension of the question above.  The most common reason
	for this is, once again, disk translation problems.  If the 
	disklabel does not agree with the disk geometry, the install will
	fail.  Other incarnations of this problem are that you can install
	DOS, then 386bsd, and DOS will be hosed, or vice versa.

	There are more than a couple of people who will blithely suggest that
	this is a good thing, and you should install 386bsd exclusively,
	job not withstanding.

6.2.3	I can use either MS-DOS or 386BSD on my hard drive,
	but shutdown -todos doesn't seem to work.

	There is a known bug in shutdown that prevents the -todos option 
	from working as advertised on all but the smallest DOS partitions.
	Many people have reported some success while using a very small
	(less than 32M) DOS partition as the first partition.

	There is a utility available for 386bsd which operates very much
	like the MS-DOS fdisk partitioning program.  You can use this program
	to mark the DOS partition active from 386bsd.  A similar procedure
	is used (fdisk in DOS) to mark the 386bsd partition as the active
	boot partition.  Boot managers are also an excellent investment for
	those individuals that need to boot both DOS and 386BSD.

6.3	Accessing the MS-DOS filesystem 

	One of the most common MS-DOS related questions (with the possible
	exception of 6.2 above) is how to access the DOS disk partitions
	from 386bsd.  One way is to modify mtools so that it recognizes your
	DOS partition.  This solution is provided by Jim Paradis 
	(paradis@sousa.ltn.dec.com):

	--------------------------------------------------------------------
	To build a /usr/othersrc/public/mtools.2.0.5/devices.c file that 
	lets you access the DOS partition, you need to know the byte offset 
	of the DOS partition from the start of the hard disk.  You would then 
	add an entry to the devices[] array as follows:

	{'C', "/dev/wd0d", <byte-offset>L, 16, 0, (int (*) ()) 0, 0, 0, 0},

	So, f'rinstance, if your DOS partition starts at the beginning of
	the disk, you'd have:

	{'C', "/dev/wd0d", 0L, 16, 0, (int (*) ()) 0, 0, 0, 0},

	On the other hand, if your DOS partition starts 32MB into the disk,
	you'd say something like:

	{'C', "/dev/wd0d", (32768L * 1024L), 16, 0, (int (*) ()) 0, 0, 0, 0},

	--------------------------------------------------------------------
	Of course, this is both the hard and VERY non-portable way of
	solving this problem.  An easier way would be to add PCFS to your 
	386bsd/NetBSD system.  Both the PC File system and PC Network File 
	System (PC-NFS) code has been ported to 386bsd/NetBSD.  These are 
	available from several sources, including the patchkit. 

	The instructions for using PCFS with 386BSD are provided by Scott 
	Miles <gt1679c@prism.gatech.EDU>. 

	    What would probably be easier would be to add a partition to 
	    the disklabel for your DOS drive and then just mount it with 
	    PCFS.  I don't know if it's in the FAQ now, I haven't read it 
	    for a while, but this is what I did:

		1) run 'fdisk' and write down the DOS partition info for 
		the start and size that it gives you.

		2) disklabel -e -r /dev/<raw device>
   		   - Add 1 to the '# partitions:', and then add another line 
   		   for the DOS partition .  Mine went in after e: as 

	   f:   130977     63   unused      0     0     # (Cyl.    0*- 129*)

	(Ed.Note:  The unused should be something else, although I really
	    couldn't tell you what. MSDOS is a recognized partition 
	    type name, maybe that should be used.  Also, make sure that
	    your c: and d: partitions do not overlap this area.  h: might 
	    be a better partition letter to use; that way the MSDOS 
	    partition is graphically separate from the rest of the BSD
	    partitions.  DO NOT USE a:, b:, c:, or d: for your DOS 
	    partition.  These are RESERVED for your BSD system and any 
	    attempt to use these for anything but what BSD uses them for 
	    will result in a completely hosed, totally dead, absolutely 
	    screwed up file system.  You have been warned! )

		3) Add a line to /etc/fstab if you want it mounted 
		automatically.
   		  Mine is:
   		  /dev/wd0f       /dos            pcfs    rw              1       2

   	    Otherwise, just mount -t pcfs /dev/<part> /<dir>

	Mount has other options that may improve performance or increase
	security for your system.  See 'man mount' for more information 
	about mounting your system read-only and other advanced features.


6.4	NFS/PC-NFS support

	The problems normally associated with PC-NFS are also associated 
	with NFS in general.  

6.4.1	Can I use 8K packets for NFS?  When I try, I have all kinds of 
	problems.

	In addition to the NE2000 card, this problem can also manifest 
	itself on other ISA networks cards that have a limited amount of
	memory.  Ken Raeburn (raeburn@cambridge.cygnus.com) has identified 
	a common problem with the NE2000 card and provided us with a work
	around:

	--------------------------------------------------------------------
	I reported previously that I was seeing problems reading files over
	NFS using the ne2000 driver; timeouts would eventually be reported, no
	data would be read.  Listing files and directories (small ones
	anyway) were not a problem.

	After playing with etherfind and kernel printfs, I've come to this
	conclusion: Fragmented 8K UDP packets from the NFS server are not
	reaching the UDP layer in 386bsd.  The Sun is sending them (according
	to another Sun spying on the network), but the UDP input routine is
	never called.  I don't know if the bug here is on the 386bsd or Sun
	side, and won't have time to look into it in the next couple of days.

	In the meantime, mounting NFS file systems with "rsize=1024" does get
	rid of this problem.

	Ken
	--------------------------------------------------------------------

	As a matter of policy, specifying "rsize=1024,wsize=1024" works very
	well also, and makes the transfers seem to run faster.


6.4.2	How do I get around the NFS "Permission denied" error?

	The problem is not the configuration of the server (unless there is
	no real requirement to run it in "secure" mode, and you happen to
	be running it that way anyway).  The problem is the fact that,
	even though mount request are sent on a privileged port, NFS
	connections are not.  This is part of secure NFS, and is not
	supported in 386BSD.
	

6.4.3	What does the message "BAD MNT RPC: RPC Authentication error; 
	why = Invalid client credential" mean when I try to mount something
	from another machine?

	Hellmuth Michaelis (hm@hcshh.hcs.de) offers the solution to this
	relatively common problem:

	You have to make sure that the user "root" is not present in more
	than 8 entries in the "/etc/group" - file on the 386BSD machine.
	Simply remove some entries and the NFS mounts will succeed.

	The problem is also explained in the Clarkson Driver documentation.
	On 386bsd, the maximum number of groups that can be associated with
	a particular user is specified in the source (in a #DEFINE).  In 
	386bsd, this number is set to 8.  So, you actually have two routes
	you can take to correct this problem.  The first is outlined by
	Hellmuth, above, and the second is to edit and recompile the NSF
	software to allow more groups.

6.4.4	What does the message "Bad MNT RPC: RPC: Authentication error; 
	why = Client credential too weak" mean when I try to mount something
	from another machine?

	This problem is a standard NFS problem; it simply means that your 
	user number is not one of the ones that can mount this NFS.  
	Normally, you will get this message when you are trying to mount 
	a filesystem from a machine that allows 'root' to mount an NFS,
	but limits other users.


6.4.5	Is there any PC software that will allow me to use my enormous PC
	with all of the unsupported hardware as a PC-NFS server?

	Yes.  It is called SOSS, and is available from MANY FTP sources.
	You will need the aforementioned Clarkson Packet Drivers for it
	to work, but that should cause too many problems for most people.
-- 
------
TSgt Dave Burgess
NCOIC AL/Management Information Systems Office
Brooks AFB, TX