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Date:      Wed, 22 Mar 2006 16:40:19 -0500
From:      John Baldwin <>
Subject:   Re: bin_48341 & Dual-Booting
Message-ID:  <>
In-Reply-To: <000001c64ddb$6bafd5a0$f5d8ae51@hal>
References:  <000001c64ddb$6bafd5a0$f5d8ae51@hal>

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On Wednesday 22 March 2006 11:20, Frank Mitchell wrote:
> Dear Matteo Riondato,
> Further investigation confirms two problems related to Heiner's.
> For Dual Booting with Windows Me I needed to retain my LBA Disk Geometry,
> as originally auto-detected by BIOS. This means 1023 Logical Cylinders and
> 64 Logical Heads, also given by Slackware fdisk.
> But FreeBSD-6.0 accepts the Default Logical Geometry supplied by the ATA
> Identify Drive Command, which means 4092 Logical Cylinders and 16 Logical
> Heads. The sysinstall fdisk in FreeBSD-6.0 sets up this CHS Geometry even
> when the desired LBA CHS Translation Geometry is specified in the BIOS, and
> even when the FreeBSD Partition was already set up for LBA CHS Geometry
> previously. You need to be aware of the need for the fdisk "G" option every
> time.
> Being new to FreeBSD, I wanted to re-run sysinstall a few times without
> disturbing my Windows Me boot set-up. So I chose the "Boot Manager = None"
> Option, intending to leave the MBR untouched while I investigated the
> possibility of booting from a Floppy. But I soon found my machine rebooted
> into FreeBSD every time. I didn't see Windows Me again until I installed the
> FreeBSD Boot Manager, which luckily dual-booted okay. (Windows Me gave
> problems using Lilo).

This is because the default boot manager windows installs just boots the
'active' slice, and sysinstall marked the FreeBSD slice as active.

> One fact may or may not be significant. My BIOS had the Boot Sector Virus
> Warning Enabled. Now every time I reboot with FreeBSD Boot Manager I get a
> bleep alarm and a Message Box saying: "Award BIOS WARNING!!! Disk Boot
> Sector is to be modified. Type "Y" to accept, any key to abort." I never got
> that with the "Boot Manager = None" Option, even though the Boot Setup was
> obviously changed.

This is expected.  The boot manager by default rewrites itself to disk each
time to save its state (this way it remembers what you booted last and uses
that as the default each time).  You can either turn off the warning in your
BIOS, or you can disable this auto-updating using boot0cfg to turn off the
'update' flag.

John Baldwin <>  <><
"Power Users Use the Power to Serve"  =

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