Patch-ID# 100027-01
Keywords: portmapper diskless client boot hang rpc panic vfs_mountroot mount root
Synopsis:Diskless clients hang; panic: vfs_mountroot
Date: 29-Mar-89

SunOS release:
	4.0, 4.0.1, 4.0.3

Bug ID's fixed with this patch:
	1013639 1018583 1018791

Patches which conflict with this patch:

Architectures for which this patch is available:
	sun2 sun3 sun4 sun4c

Obsoleted by:
	4.1

Problem description:

This patch addresses two diskless client boot problems:

 Problem 1 (Bug#1018583 & 1018791):

   An incorrectly implemented portmapper on the network can prohibit 
   all diskless clients from booting since the boot program takes 
   only the first valid reply to its broadcast portmapper rpc request 
   for bootparams.  Typically the client's boot will fail with:

           whoami RPC call failed with status 16
           panic: vfs_mountroot: cannot mount root

 Problem 2 (Bug#1013639):

   Due to limitations in the boot PROM and client boot program, often 
   with a busy ethernet if there is much packet activity directed at
   the diskless client during boot it can be very slow to boot or may 
   eventually timeout and not complete its boot.  Client console
   messages during boot indicating a sleep state, unusual status codes,
   exception messages, or receive and missed packet type errors are
   typical of this boot problem.
 
   In addition to these software patches which specifically address
   client boot problems at the rpc level, there could continue to be
   problems earlier in the boot during the tftp stage.  If problems
   at the tftp stage exist there is a new hardware cpu PROM revision
   of 3.0 which should be requested from the Sun Field Hardware
   support channels.  When requesting PROM changes - please refer to 
   bug#1013639 only!
 
   The boot.sun[234] program fixes affecting this bug (1013639) were 
   incorporated in the 4.0.3 release and consequently problems related 
   to this bug seen in 4.0 and 4.0.1 may not be seen under 4.0.3.  
   However the potential for boot problems due to a PROM revision less
   than 3.0 still exists under 4.0.3.