From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX" 17-JAN-1993 00:01:01.47
To:	info-vax@kl.sri.com
CC:	
Subj:	Re: Remotely rebooting vms


There's been a lot of discussion about remotely booting VMS, and someone
had asked me earlier whether VMS would ever allow a shutdown to the
console prompt, rather than going into a loop and displaying a message to
use the console.

I'm a bit puzzled at some of the questions here, in particular from those
having trouble issuing reboots while dialed in; I do that all the time and
never have a problem with it.

But to the point (or points)...  First, the major reason VMS doesn't shut down
to the console prompt is that the way to do that is to execute a HALT
instruction and since most people have their systems set up to do a reboot
on halt, that's not very useful.  However, some of the newer systems do have
the ability for the operating system to tell the console firmware "just this
once, do X instead of the default halt action".  I am told that there are
no current plans to change VMS to use this on systems which support it.

Generally, the reason you'd want to shut down to the console prompt is when
you want to do a MOP TRIGGER of the system; VMS doesn't support MOP TRIGGER
requests (probably a good thing), but the VS3100 and VS4000 series do
support it when at the console prompt.  So, how to get there?

Keith Parris of VMS Development stopped by yesterday and showed me an article
he had written for the August 1992 "VAXcluster System Quorum" magazine, which
is available at no charge (I don't know if you have to be a VAXcluster 
customer or perhaps just a Digital services customer).  To get a
subscription if you don't already have one, call Susan Pillsbury at
508-467-7180.  The article is "Building Large VAXcluster Configurations",
but part of it deals with the issue of how to bring down a VMS system so that
it will go into console mode, without hacking up VMS to do a HALT after the
shutdown.  The technique described really is only applicable to cluster
satellites, involving setting the boot server to load READ_ADDR.SYS instead
of the normal system image and doing a reboot, since READ_ADDR does a halt
after it's finished.  But the article may be helpful otherwise.

Also, the VAXcluster Console System (VCS) can be used to control booting
of multiple nodes.
--

Steve Lionel                    lionel@quark.enet.dec.com
SDT Languages Group
Digital Equipment Corporation
110 Spit Brook Road
Nashua, NH 03062