On 19 Jun 1997, Peter Simons wrote:

   > I have recently installed NetBSD 1.2.1 on a Pentium machine with IDE
   > hard disk. So far everything works fine except for this:
   > 
   >  | [date] peti /netbsd: /dev/wd0a: file system not clean; please fsck(8)

My experience with this is that only if fsck is run in single user
mode with the filesystems unmounted will it mark the root filesystem
as clean.  Otherwise, the 'not clean' message seems to persist.  I
think the rest of the filesystems get marked clean just fine.
However, it seems like that (unmounted filesystems) is the state of
the machine when fsck gets run by /etc/rc, so I'm not sure why there
is a difference between booting single user and running fsck and
letting /etc/rc do it.

In any case, you can clean the filesystem in single user mode and as
long as you don't reset the machine or turn it off without halting it,
the 'not clean' message won't reappear.

Cheers,
Brook