Select the drives you wish FreeBSD to be able to use.

If you are going to actually install some portion of FreeBSD on a
drive, then PLEASE BE VERY CERTAIN that the Geometry reported in the
Partition Editor (see Installation Menu) is the correct one for your
drive and controller combination!

IDE drives often have a certain geometry set during the PC BIOS setup,
or (in the case of larger IDE drives) have their geometry "remapped"
by either the IDE controller or a special boot-sector translation
utility (such as that by OnTrack Systems).  In these cases, knowing
the correct geometry gets even more complicated as it's not something
you can easily tell by looking at the drive or the PC BIOS setup.  The
best way of determining your geometry in such situations is to boot
DOS (from the hard disk, not a floppy!) and run the ``pfdisk'' utility
provided in the tools/ subdirectory.  It will report the geometry that
DOS sees, which is generally the correct one.

FreeBSD does its best to guess all of this automatically, of course,
but it sometimes fails which is why it's a good idea to check it.  The
Partition Editor has a `(G)eometry' command that will allow you to
change it as necessary.