Sorry - plaintext this time - Disk geometry and two OSes.

Slick Bo slickwillbo42 at
Tue Aug 5 01:08:33 UTC 2008

Hi everyone,

I have two 37GB (nominally 40GB) IDE/ATA disk drives. I'm trying to leave my Windows XP SP1 installation on the one that shows up as "0" (ad0 in sysinstall),
and giving the entire other drive to FreeBSD. When creating a boot
agent for the 0 drive, sysinstall complains about incorrect disk

I have tried checking the geometry of my disks.
However, my BIOS does not display it. The only information it displays
about each disk is the capacity in megabytes (40000 MB), and the "type"
(whether it's "auto" or "off"). And pfdisk.exe doesn't work; it's
reportedly not allowed to directly access the disk. I considered
running chkdsk, but it seems it needs to run at boot time in order for
it to actually check the 0 drive, and I have no way of catching the
output (microsoft claims it dumps information into an event log, but it
doesn't, or I can't find it in the place they claim).

other note. On my 0 drive, there are two primary partitions. The first
one is a 30 MB FAT partition with the label msdosfs/DellUtility (my
computer is a Dell). I'm assuming the boot information is on this partition... will sysinstall know to put the bootloader on that partition?

seen a few people on this mailing list say that disk geometry really
doesn't matter that much, and the OS usually works fine despite
apparent errors. But I'd prefer to be able to keep my windows installation.
If I let sysinstall change the disk geometry, will it create problems
for the files on "0" and the WinXP installation? If so, do you know of
an alternate way to find the disk geometry, and should I directly give
these results to sysinstall? Will that fix my problem?

Alright, I appreciate it. Thanks a lot in advance,
Will L.


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