Gotcha: Configuring a local disk for swap on a SS1 under 4.1.1

[nobody at kodak.com]

Over the holidays I upgraded one of my servers from a 4/280 to a 4/490 and
in the process upgraded the OS from 4.0.3 to 4.1.1.  This server servers a
few 4/110's and several Sparcstations (1 and 1+).  Most of the SS have a
local 104meg disk that is used for swap only (Twiddling bits in images can
us lots of swap space.)  

Under 4.0.3 the config line in the kernal configuration file looked like:

	config vmunix swap on sd0b

Under 4.1.1 that does not work.  The SS download the kernal from the
server and proceeds with the bus probe.  The it is supposed to show where
the root, swap and dump areas are located.  It displays the root area and
then hangs.

After some hacking around with a large amount of help from one of the
local Sun Office people who came out to help (Thanks, Bob) we found the
following worked:

	config vmunix swap on type spec sd0b

This line is used to set up the confvmunix.c file located in the kernel
make directory.  This file has structures as to where the root, swap, and
dump area are located.  The man pages for config(8) do not mention this as
a legal syntax for the swap area.  

We couldn't find this in the manual.  If anybody knows anything about
this, I'd appreciate hearing about it.  

Charlie Dennett          | Rochester Distributed Computer Services
Mail Stop 01816          | Internet: dennett at Kodak.COM
Eastman Kodak Company    | System Manager - Imaging Science Lab
Rochester, NY 14650-1816 |