>We've deployed NetBSD 1.6 on half a dozen servers.  We have the kernel
>compiled with all the ALTQ & IPSEC tags enabled on half the servers - the
>other half don't have ALTQ.  Now, we're having a strange problem with the
>ALTQ servers - they seem to corrupt their own hard drives.  All the
>servers report hard drive problems, and if we fsck them, we get this:
>
>** /dev/rwd0g
>BAD SUPER BLOCK: VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST
>ALTERNATE
>
>LOOK FOR ALTERNATE SUPERBLOCKS? [yn]

	my guess is that you are mixing pre-UFS2 and post-UFS2 fsck/kernel.
	you can't mix those two.  see src/UPDATING.

itojun