Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: dinah@shell.UUCP (Dinah Anderson)
Newsgroups: comp.sys.sun
Subject: Re: Modifying default number of buffers
Message-ID: <8901111511.AA26231@dogwood.IC.shell.com>
Date: 15 Jan 89 21:19:07 GMT
Sender: usenet@rice.edu
Organization: Sun-Spots
Lines: 23
Approved: Sun-Spots@rice.edu
Original-Date: Wed, 11 Jan 89 09:11:53 CST
X-Sun-Spots-Digest: Volume 7, Issue 104, message 4 of 13

>I would like to be able to modify the number of buffers selected by the
>kernel.  It appears to do this based on the amount of memory available.  I
>couldn't find anything in any of the system's .h files to allow tuning of
>this.  Is there some way to do this without source?

I am assuming you are talking about disk buffers (NBUFS). I can tell you
how to do that.

On your running system: (This examples changes the value to 700.) We were
running 3.2 on a Sun 4.

adb -w /vmunix
nbuf?W 2bc                      (which is 700 decimal)

Now re-boot.

Checked with:

adb -k /vmunix /dev/mem
nbuf?D  (shows in decimal what this is in /vmunix)
nbuf/D  (shows in decimal what this is in /dev/mem)

(Note: This value also shows up when you boot.)