Subject: Re: nore on disk stats
To: Chris G Demetriou <>
From: Daniel Carosone <>
List: tech-kern
Date: 11/10/1995 16:50:15
> > Now, the question I have is, what units should data transfer rates be 
> > in?  As Mike Hibler pointed out to me, counting bytes/words/longs or even 
> > blocks could potentially wrap the counter very quickly on a busy 
> > fileserver, so it seems as if attempting to do so over the long-haul is 
> > dubious.
> Quads are your friends.  I sincerely doubt that you'll wrap a quad
> counter "very quickly" (or even "at all" 8-)...

Just as long as the code doesn't make this assumption :-)

> It's not inconceivable that, for long periods of time, the busy count
> won't drop to zero.  This is especially true of devices intended for
> high-use situations, like 'ccd' units. 

One question, for jason: Given a ccd, all the io's done to that ccd
are counted against the ccd - but are they also counted against the
underlying devices that make up the ccd?

I can think of cases where either "yes" or "no" would be the desirable