Ran into an interesting one setting up my cpu server. The following reliably freezes the box:
# echo dma on >/dev/sdC0/ctl # 9fat: Leaves the console totally unresponsive, no ^T^Tp, no ^P. rc -x on 9fat: gives "rfork e" as the final command. sdC0 is a cdrom. I can turn dma on for my sata disks (sdE0/sdF0) no problem. -sqweek
