Subject: "block size invariant failed" panic (was: Re: scsi hardware error)
To: None <>
From: Steven M. Bellovin <>
List: netbsd-users
Date: 01/02/2002 15:08:08
To further check out my hardware, I tried dd'ing one of my drives to
/dev/null.  The result was a panic, with no sign of a hardware error...

I tried

	dd if=/dev/sd1e of=/dev/null bs=10240

It churned for a while, then said "panic: getblk: block size invariant 
failed".  (This is under NetBSD 1.5.2.)

Is this something to worry about?  Or is this "normal" when reading a 
block special device without checking if the file system size is, in 
fact, a multiple of the blocksize I specified?  (Note that I did *not* 
say /dev/rsd1e.)

I'd try to get a dump, but with drive 0 showing serious signs of ill 
health I don't think I could write the dump anywhere.

		--Steve Bellovin,
		Full text of "Firewalls" book now at