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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msuinfo!gmi!zombie.ncsc.mil!MathWorks.Com!yeshua.marcam.com!charnel.ecst.csuchico.edu!psgrain!news.tek.com!news!phils From: phils@satori.tv.tek.com (Phil Staub) Newsgroups: comp.os.386bsd.questions Subject: Re: dos 6.2.2 & FreeBSD1.1.5 Date: 03 Oct 1994 16:57:29 GMT Organization: Tektronix TV Products Lines: 91 Message-ID: <PHILS.94Oct3095729@satori.tv.tek.com> References: <36j05b$c1i@pendragon.jsc.nasa.gov> <DEAN.94Oct1162243@deanstoy.wa.com> NNTP-Posting-Host: satori.tv.tek.com In-reply-to: dean@deanstoy.wa.com's message of 01 Oct 1994 23:22:41 GMT In article <DEAN.94Oct1162243@deanstoy.wa.com> dean@deanstoy.wa.com (Dean M. Phillips) writes: > > > I have problem when I put dos with the FreeBSD. > > For some reasons, the UNIX partition cannot boot. > > > Any ideas > > Provide some detail on what you did and what happens when you try to boot > FreeBSD and maybe then someone might have some ideas. We don't read minds, > you know. :) > --------------------------------------------------------------------------- > Dean M. Phillips PGP key available on request dean@deanstoy.wa.com > TEMPORARY ADDRESS: dphill@leland.stanford.edu Sept. 23 through Dec 16 ONLY > -- I'm fresh from a frustrating (but eventually successful) weekend having resolved a problem which sounds suspiciously like this one. See if this is anything like your situation. The scenario: Controller = BusLogic BT946C. Disk = Seagate ST31200N. I just installed this big SCSI disk, so that I could dedicate 250 Meg for DOS and 750 Meg for FreeBSD (note relative importance here 8-)). Since I wanted to be able to access the DOS partition from FreeBSD, I loaded it first. OK so far. Then I begin to load FreeBSD 1.1.5.1. When it gets to the point where you do the kernel copy, then reboot from the hard disk, I get a message from the boot selector (os-bs release 1.35): no operating system. Hmmm. So I repeat the process, after having removed os-bs. This time I get NOTHING when trying to re-boot FreeBSD. No messages, nothing. My perception is that somehow the pointers to the FreeBSD bootblock must not be getting handled correctly. Like maybe being incorrecly translated from cylinder/head/sector to logical block address, as might happen if the BIOS and the partition table had different ideas about the disk geometry. I had noted a comment in the installation process when it discovered that my disk had more than 1024 cylinders that "certain hardware" would not allow FreeBSD and "other operating systems" (I believe is what it said, referring to DOS) to coexist on this drive. I smugly thought to myself "This is why I bought a SCSI disk instead of one of those poorly supported big IDE drives with > 1024 cylinders" and assumed that I would have no problems. The installation script also made the assumption that there would not be a problem. This was my biggest mistake. So I started putting FreeBSD at the beginning of the drive, leaving a partition big enough for DOS at the end. Now DOS FDISK reports "not enough room on drive". Now I'm sweating. Then I started thinking about how DOS would have to deal with this big disk if it were to be given the entire chunk to manage. Given that DOS seems to insist that there can be no more than 1024 cylinders, I figured it must be re-figuring the disk geometry into something more to its liking. So, I got a brainstorm. I came up with the idea to use DOS 6.xx's MSD.EXE program to see how DOS would treat the disk. Doing this, I found that DOS sees it as 1006 cylinders, 64 heads, 32 sectors per track, not the 2700 cylinders, 9 heads, 84 sectors per track reported when the disk is probed at FreeBSD boot time. So I shrunk the DOS partition back down to 250 Meg, and re-installed FreeBSD using these values. Voila! Life is good again. FreeBSD boots just fine. I re-installed os-bs, and it now boots either dos or bsd as advertised. Now, there may have been a quicker or better way to discover the DOS-apparent geometry, but I don't have a lot of other tools, and this worked for me. One bit of puzzlement, though. MSD.EXE reported two different geometries for the C: drive. One said 1006 cylinders, 64 heads, 32 sectors. The other said 28756 (or thereabouts) cylinders, 60 heads, 30 sectors. I noticed that when I shrunk the C: drive to 250 Meg, the first geometry reported changed to 250/64/32, but the second was unchanged. This was a big clue as to what to report to FreeBSD. I'm sure there's an explanation, but right now I'm too fed up with messing with this to care what it is. Sorry for the novellette, but I hope it provides some insight into something to try. Phil -- ------------------------------------------------------------------------------ Phil Staub, phils@tv.tv.tek.com Tektronix Television Division (503) 627-6910