Starter problems with partitioning the harddrive

Hi list,

I've got a pretty cheap Sparc5 170 which runs proper with Solaris 8.

It is equipped with
- 18GB HD internal
- CD-ROM Drive
- 2nd Ethernet
- 21" Monitor (stolen from our CAD-System;-)

Now I wont that thing to lear linux (perhaps I should do it also;-) but by 
using yast2.

After teaching the root passwd and a new user yast2 starts to prepare the 
sda (the one and only hd).
It seems to start the preparing of the disk but after a while (appr. 2min) 
there's shown a message that fdisk is'nt able to partition the hd.

Everything is done by using the defaults without loading any modules 
manually.
I think I'm basicly wrong by doing erverything with the default values?!

Any ideas would be very welcome.

Regards
Peter Josten