a bsd.rd upgrade issue for macppc

[daemonfowl]

Hi !

A while ago I tried upgrading my OpenBSD box .. it's an imac running current .. when I boot on bsd.rd and chose an ftp server it stops at [anonymous] :
No file or folder ...

and when I tried installing from within a partition (/ or /home ) using disk option I'm asked if the partition is already mounted , I say no and when I try mounting it it says : device busy ..
I tried it many times.
Is there some current issue with macppc (bsd.rd) ?
where should I preferably place the sets for a disk install option?
I can't upgrade using cdrom as it became lame.

Thanks in advance !