Upon typing 'reboot' the kernel dropped into ddb. I ran 'vnconfig' a few minutes earlier to read iso image, which I think could have attributed to the kernel crash.

uname -a
NetBSD dhcli-192-168-0-4.netctl.net 3.0_BETA NetBSD 3.0_BETA (CUSTOM) #2: Mon Apr 11 16:58:52 UTC 2005  roman@athlon1000:/opt/obj.i386_tbird/sys/arch/i386/compile/CUSTOM i386

uvm_fault(0xcb48d464,0,0,1) -> 0xe
kernel: page fault trap, code=0
Stopped in pid 379.1 (sh) at netbsd:spec_ioctl+0xe: movl 0xc(%eax),%esi

spec_ioctl(cb8bdd54,c0568500,cb489b28,80047476,cb8bdec8) at netbsd:spec_ioctl+0xe
VOP_IOCTL(cb489b28,80047476,cb8bdec8,3,ffffffff) at netbsd:VOP_IOCTL+0x40
cttyioctl(100,80047476,cb8bdec8,3,cc6af1a8) at netbsd:cttyioctl+0x6e
spec_ioctl(cb8bddcc,c0568500,cb4e9404,80047476,cb8bdec8) at netbsd:spec_ioctl+0x3e
VOP_IOCTL(cb4e9404,80047476,cb8bdec8,3,ca5e024c) at netbsd:VOP_IOCTL+0x40
vn_ioctl(cc6ae2a4,80047476,cb8bdec8,cc6af1a8,0) at netbsd:vn_ioctl+0x113
sys_ioctl(cb7915b0,cb8bdf70,cb8bdf68,0,0) at netbsd:sys_ioctl+0x22f
syscall_plain() at netbsd:syscall_plain+0x93
--- syscall (number 54) ---
0xbdbb04eb: