Bug#379512: partman doesn't always guess right geometry, doesn't allow geometry to be specified
Installing from the floppies here:
partman doesn't always guess the correct geometry when partitioning and
there is no valid partition table. This causes grub to fail after reboot
on systems where the guessed geometry is not appropriate (i.e. CHS-only
BIOSes). In my case, the correct geometry is 2100/16/63, and partman
guesses 131/255/63 (which is the kernel's logical geometry). There is no
way to tell partman what geometry to use. It is possible to work around by
using fdisk to create a blank partition table with the correct geometry
before starting partman.
partman should at least offer the choice between the kernel's physical
and logical geometries when creating new partition tables, but the ability
to enter a geometry would be best.