Samsung SSD X5 with OpenBSD - possible ?

I'm struggling a bit as to what I need to do next here.

Any time in the past I've connected a USB stick etc. to OpenBSD, everything happened automagically in terms of recognition and assigning a /dev/sd.

However this time, its different.  This is the only line that appears in dmesg when I plug it in:

ugen0 at uhub0 port 4 "SAMSUNG ELECTRONICS CO., LTD Portable SSD X5" rev 2.01/4.45 addr 2

sysctl hw.disknames remains unchanged

Any ideas ?