today, I've tried to install NetBSD 5.1 on an external USB drive. The third attempt to install the OS finally went through the installation process till its end.
Then I configured Grub2 on the internal HDD to start NetBSD from the external drive. The boot process starts but then suddenly stops (not necessarily at the same position!). After some minutes this message appears:
uvm_fault (0xc0b82a00, 0, 1) -> 0xe
fatal page fault in supervisor mode
trap type 6 code 0 eip c0767a89 cs8 eflags 10282 cr2 0 ilevel 4
kernel: supervisor trap page fault, code=0
Stopped in pid 0.39 (system) at netbsd:usb_allocmem+0x49: cmpl 0(%edx), %ebx
Think, it was a bad idea to install NetBSD to an external drive, wasn't it?