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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!doc.ic.ac.uk!uknet!rook.ukc.ac.uk!dac From: dac@ukc.ac.uk (David Clear) Newsgroups: comp.os.386bsd.questions Subject: Problems installing NetBSD to coexist with DOS. Message-ID: <1627@rook.ukc.ac.uk> Date: 22 Apr 93 09:39:35 GMT Organization: Computing Lab, University of Kent at Canterbury, UK. Lines: 91 Before I start I must confess my complete ignorance of PCs. Before UNIX was available on them they never interested me. Now the plea for help: A friend has given me his Dell 433/M (386SX + 240Mb IDE disk I believe) to install NetBSD on by Saturday. I can install it on the whole disk with no problem. The problem is that, for some reason best known to him, my friend wants to dirty his machine by keeping MSDOS on it. Repartitioning a DOS disk has me baffled. As described in the NetBSD documentation I ran the FDISK program to do the repartition. The first partition I created was a 120Mb primary DOS partition. What do I do now? I created an extended DOS partition of 114Mb (the rest of the disk) for NetBSD. I figured that I had to create a real partition just to have something in the DOS partition table. The NetBSD install notes tell me to remember the start sector and length, as given by FDISK. I haven't managed to get FDISK to tell me these. It just says how big the partitions are (in Mb). I used Norton's 'System Info' to tell me the partition addresses. But then when I took the start side/tracK/sector and end side/track/sector and multiplied it out by the disk geometry (722 cyl, 13 sides, 51 spt) the numbers did't equal the reported partition size. I played around with the numbers and found a start sector number which I think didn't hit the DOS partition. I gave these to the NetBSD install program and the install started. At the point where the disklabel happens, it said: "Overwriting disk with DOS partition table? (n):" This threw me as it's not in the install notes and I haven't a clue what it's asking. Is it saying it's just going to stamp on a disk which HAS a DOS partition table or is it saying it's going to WRITE a DOS partition table or that the disk area it's writing to is COVERED by an existing DOS partition? Anyway, whether I entered 'y' or 'n' the results were the same (it seems). After the install, which went fine and the OS did boot from the hard disk, I rebooted from an MSDOS system floppy and ran FDISK again to look at the partition table. The only entry in there was the NetBSD root partition of type 'NON_DOS'. So that's one problem - the co-existent installation attempt was a disaster. I checked the install notes for 386BSD and that says to make just one partition for DOS and just leave the rest of the disk uncovered by any DOS partition. I haven't tried that yet but will do later. Will the NetBSD install program append that unreferenced disk area to the DOS partition table? Is that how it's meant to work? If that's the case, how do I find the sector size and offset of that area? Finally, the NetBSD system I installed worked fine. Except that, doesn't 386BSD have a 'reboot -todos' command or something similar? I couldn't find a way to take the system down so it would reboot to DOS. Now something a little worrying. After completely bogging the installation, I tried to re-install DOS. I rebooted from the DOS5.0 install disk and it said 'Determining your configuration', accessed the disk and hang. I had to boot from another system floppy and use FDISK /MBR (and my DOS manual doesn't actually quote what that command does). Also, before I have completely wrecked a 386BSD installation to the point where in would no longer install from scratch correctly. This was because the geometry on the disk label was wrong. Question: should install programs look at the disk at all if you want to do a complete re-installation? I've borrowed a small DECstation316 PC which I installed the minimum 386BSD distribution on. Then I replaced it with MSDOS, and then I went to re-install it and it said: "It seems 386BSD has already been installed. Install over it?" I think this is awful. What crud is the installation leaving on the disk to make it know it has been there before? Is there any way to remove it? Anyway, all that doesn't worry me right now. I've got two days left - help would be appreciated!! I'm sure this sort of thing is a breeze if you know PCs. Apologies again if these questions are basic. I've spent more time in the past two evenings sitting in front of a PC than I have ever done I think... Cheers, Dave.