Quoting haury@sagem.fr,

> 2) it is not possible to share an IDE disk between DOS and NetBSD if the
>    disk geometry have more than 1024 tracks. DOS fdisk don't store the real
>    geometry but something like tracks/2 and nb_heads * 2. NetBSD tries to use
>    this fake geometry at boot time even if you tell to disklabel the right one.
>    (result: the boot still frozen with disk I/O errors)

This _is_ possible.. as long as:

1) The DOS partition does not exceed 1024 cylinders.
2) If the NetBSD partition has to be used for booting, it has to start well
   below 1024 cylinders, so that the BIOS (called by the bootblocks) is
   able to find the kernel.
3) Stuff like the On-track Disk Manager or BIOS options to fake disk
   geometry are not used (i.e. the geometry used by DOS has to be
   the same as that for NetBSD).

- Frank