Subject: Re: rewriting disklabel
To: David Brownlee <email@example.com>
From: Frederick Bruckman <firstname.lastname@example.org>
Date: 05/09/1998 01:25:54
On Thu, 7 May 1998, David Brownlee wrote:
> Almost certainly nothing.
> The RPM entry can be use to optimise head movement, but is
> pretty much irrelevant for most NetBSD ports (it could still
> be useful for vax and hp300 for example).
> -=- "cold nights, dark days..." -=-
> On Tue, 5 May 1998, John B. Lee wrote:
> > Being new to BSD, I'm also new to disklabels. Just out of curiosity, what
> > would happen if I rewrote a disklabel to a disk, with only the rpm entry
> > changed? What does the rpm entry do anyways? Does the kernel use it in
> > some manner?
That's actually the "rotdelay" built into a filesystem. The RPM entry in
the kernel may be used by `newfs' when you invoke it without the `-d'
switch, or maybe not. You can change the rotdelay on the fly with
`tunefs', regardless. I have experimented with that on mac68k, but I can't
say that its led to any noticable difference in performance.