Date: Tue, 13 Sep 2005 12:01:36 -0700 From: "Gayn Winters" <gayn.winters@bristolsystems.com> To: "'Alex Zbyslaw'" <xfb52@dial.pipex.com> Cc: freebsd-questions@freebsd.org Subject: RE: Fixing a MBR (and more) that ??? trashed Message-ID: <00f701c5b895$9914eb10$c901a8c0@workdog> In-Reply-To: <43269684.60609@dial.pipex.com>
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> -----Original Message----- > From: Alex Zbyslaw [mailto:xfb52@dial.pipex.com] > Sent: Tuesday, September 13, 2005 2:06 AM > To: gayn.winters@bristolsystems.com > Cc: freebsd-questions@freebsd.org > Subject: Re: Fixing a MBR (and more) that ??? trashed > > > Gayn Winters wrote: > > >Life was good with my dual boot w2k/fbsd system until > >I wanted to add another disk. The w2k operating > >system, when booted, saw the new hardware, "installed" it, > >and demanded that I reboot. OK, but when I did, the > >FreeBSD boot manager was trashed. Its menu looked like: > > > >F1 ??? > >F2 FreeBSD > >F5 > >Default: F# > > > >I could not boot either operating system. In fact the only keys that did > >anything were ctrl-alt-del! I removed the new hardware and using Fixit > >on the 5.4 release CD, I tried > > boot0cfg -B ad1 > >This recovered the boot manager, and allowed me to boot w2k, but FBSD > >wouldn't boot. Pressing F2 in the boot menu still did nothing. > > > > > How far into the disk was FreeBSD? I had a similar problem until I > specified "-o packet" > i.e. > boot0cfg -B -o packet ad1 > Ah ha! FreeBSD started at cylinder 41610. Looks like I definitely needed the packet option. > You could also try writing the boot manager using sysinstall/boot CD: > http://www.freebsd.org/cgi/getmsg.cgi?fetch=611111+617364+/usr/local/www /db/text/2005/freebsd-questions/20050626.freebsd-questions --Alex You know, I think I tried that, unsuccessfully. Here are Gary's thoughts: > -----Original Message----- > From: Gary W. Swearingen [mailto:garys@opusnet.com] > Sent: Tuesday, September 13, 2005 8:03 AM > To: gayn.winters@bristolsystems.com > Cc: freebsd-questions@freebsd.org > Subject: Re: Fixing a MBR (and more) that ??? trashed > > > "Gayn Winters" <gayn.winters@bristolsystems.com> writes: > > > 2. Was the disk label on the FreeBSD slice ad1s2 really corrupted? > > Unlikely, at least until you ran sysinstall. I've never figured out > how it handles existing disklabels. Badly, in my limited experience. > Use "bsdlabel" from a rescue CD and see what you have there. If > you're concerned about the mount points, mount the "/" device and look > in /etc/fstab. > > > 3. I couldn't get sysinstall to fix this mess - even though I thought > > it was fixing the FreeBSD partition mount points and applying a new BSD > > Boot Manager. I couldn't get these "fixes" to "commit". Can sysinstall > > fix this mess without reinstalling? > > I'd use a rescue system -- either CD or another hard disk. > > > 4. How do I avoid this situation when I add another disk? > (Other than trash the w2k partition.) > > I don't know about dual-booting MSFT, but you could "dd" the first > tracks of the HDD and it's primary partitions to files on a formatted > floppy or two for safe-keeping, before doing anything that could mess > up the boot records. You might want to save the first track of your > FreeBSD primary partition too. You can then put them (or selected > sectors) back with "dd" from most unixy rescue OSes. Regarding repair: Alex (above) seemed to think sysinstall would do it, but I tried a couple times (reloading FreeBSD each time) and gave up. Given Gary's comments, I suspect that I corrupted the disk label on the FreeBSD partition mis-using sysinstall somehow. I like Gary's idea of a spare copy of the MBR saved on a floppy. Seems like good insurance. Regarding avoidance: I would still like to add additional hard drives to my dual boot systems. Is there any safe way to do this? Thanks!!! -gayn
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