odd crash on -STABLE box

[Rob Byrnes]

I checked by Alpha this morning after it's been running fine for a while 
and saw this on the terminal (hand transposed):

Jun 14 08:54:55 erwin getty[2087] : getty : retreiving gettytab entry 
'default': Device not configured
Jun 14 08:54:55 erwin getty[2087] : getty : retreiving gettytab entry 'Pc': 
Device not configured
Jun 14 08:54:55 erwin getty[2087] : getty : retreiving gettytab entry 'Pc': 
Device not configured
Jun 14 08:54:55 erwin tc setattr /dev/ttyv1: Operation not supported
Jun 14 08:54:55 erwin init: getty repeating too quickly on /dev/ttyv1, 
sleeping 30 secs

Tried to halt the box nicely, this error popped up:

[root at erwin] /: halt
	spec_getpages : [#da/0] I/O read failure: (error 6) bp 0xfffffe0004a53b70 
vp 0xfffffe000b683ec0
		size: 65536, resid: 65536, a_count: 65536, valid: 0x0
		nread: 0, reqpage: 0, pindex: 0, pcount: 0
/sbin/halt: Input/output error

So I had to hard reset the box.  It came back OK after a fsck, nothing in 
the logs at all

root at erwin ~ % uname -a
FreeBSD erwin.number6 4.8-STABLE FreeBSD 4.8-STABLE #0: Mon Jun  9 16:34:34 
EST 2003     root at erwin.number6:/usr/obj/usr/src/sys/ERWIN  alpha

Any clues as to what went awry?

Cheers,
Rob