Date: Thu, 1 Aug 2002 21:50:22 +0200 From: "Siegbert Baude" <Siegbert.Baude@gmx.de> To: "Cherie & John Carri" <cjcarri@earthlink.net> Cc: <freebsd-questions@freebsd.org> Subject: Re: Can FreeBSD make a hard drive unbootable by other OS's ? Message-ID: <00bd01c23994$ad6dea40$406a3c86@whwurm.uniulm.de> References: <KJD9TN32KIEBJH4YBADCXVMG4ZMGDB6.3d4740d5@sparky> <002701c238a2$687bdac0$406a3c86@whwurm.uniulm.de> <1028177573.19892.17.camel@bilbo.ourhome.org>
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Hi John, please for the sake of the archives let the list cc'ed so that people searching there will be able to see what steps you actually did and which was the clue to your problem. > > Other things to check: Where did you tell Mandrake to install it's lilo? > > If it's a Linux only disk, the correct place would be the MBR. If you've > > chosen to install it in a partition, look if this one is set active > > (i.e. bootable). > Thank you for your detailed and carefully thought out email. Yes, I > told Mandrake to intall lilo in the MBR (/dev/hda). > > > If your computer's BIOS is quite old, the 1024 cylinder problem could > > touch you (that is not a 1Gig border). Depending on your BIOS and > > mapping of your disk, this can be any value from 512MB (on old BIOS > > without EIDE support) to 8GB (1024 cylinders with a single cylinder set > > to the maximum value). > --------------------------------- > I see, I didn't know that. However I don't think this is my problem; > when I posted my first email I had a small (approx 60 MB, way under even > the 512 MB limit) first partition, mounted as /boot. > > After hearing about "fdisk /mbr", I wiped my drive, made a FAT > partition, booted from a DOS floppy, and ran fdisk /mbr. I then > reinstalled Mandrake 8.2, this time with a 256 MB root (/) partition as > the first partition on the drive, and again with LILO installed to the > MBR. I was still unable to boot from the hard drive, though I can boot > from the boot floppy I created during the install (as well as from the > CDROM). > > > If you are able to boot from the Linux-CD, go there into a console, > > write down all the settings fdisk shows about your partition layout, do > > the "dd" steps mentioned in the other thread, redo fdisk with exactly > > the same values you wrote down before, make sure you have the correct > > partition active, check your /etc/lilo.conf to install lilo in the MBR > > (i.e. /dev/hda not /dev/hda1) and start /sbin/lilo once again. > -------------------------------- > I'll try this out today. One thing I'm not clear about - the reference > to making the correct partition active. Is that something set up in the > PC's BIOS, or in /etc/lilo.conf? I let the Mandrake installer setup > LILO automatically - this has proved reliable for me in the past, as > I've installed Mandrake 8.2 on several PC's without trouble. When the BIOS boots it looks, which of the partitions is set active and will use the boot sector of this partition to continue the boot process. This is set within fdisk. The DOS one will do this automatically for the first FAT partition (c:) I believe (didn't use this for along time), the Linux fdisk has a command for this and will show the active partition marked with an asterisk. Windows at least needs this, so set the windows system partition active. I think lilo in the MBR won't need it to boot Linux, but am not completely sure. > > I currently have the hard drive as the primary IDE master, and an > ATAPI IDE CD-RW as the secondary IDE master. I can boot from both the > floppy and the CD-RW, but not from the hard drive. That is really strange. I would recommend to first try, if you are able to boot plain DOS from the HD. So boot from DOS floppy, make a small FAT partition with fdisk on your hard drive, do fdisk /mbr and format c: /s This will make your hard disk bootable for DOS. Now try every possibility in your BIOS to get this booting, this has to work first! Afterwards redo your fdisk and the windows installation and then your Linux/FreeBSD/whatever installation > > If you then face any problems, it is not because of earlier FreeBSD use > > of this disk, as after the "dd" step the disk completely forgot about > > this. > ----------------------------------- > I ran the DOS "fdisk /mbr" command from a DOS boot floppy, and saw the > hard drive light come on for a few seconds. Has this achieved the same > thing as the "dd if=/dev/zero of=/dev/rsd0 bs=512 count=1" command, or > should I run the dd command while booted into Linux ? fdisk /mbr is the DOS way of applying a valid MBR. The dd comand just writes zeros to the MBR, so that there is no valid MBR, but all tools will think this is a brand new never touched disk. Both ways should achieve to get rid of any FreeBSD "dangerously dedicated disk" hangovers on the disk. So this doesn't anymore look like the core of your problem to me. > I just ran fdisk /hda on the the Linux box (not DOS fdisk, Linux > fdisk). > The response I got was a warning message "The number of cylinders for > this disk is set to 8912....this could cause certain problems with: > (1)Old versions of Lilo (2)boot/partitioning software from other OS's, > eg DOS fdisk" > So my attempt to fix the mbr with "fdisk /mbr" clearly didn't work. > I'll try the "dd" command now... No, this conclusion isn't valid, as the Linux fdisk warning is perfectly right. All disks bigger than 8GB have more cylinders than 1024 (due to specification limitations for the size of a cylinder; there are simply not enough bits reserved in a PC partition table for it.) so fdisk just tells you to pay attention that some OSs won't boot partitions above cylinder #1024. That's all and it's correct. Ciao Siegbert To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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