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From: yerazuws@CSV.RPI.EDU.UUCP
Newsgroups: mod.computers.vax
Subject: Re: Alternating Ultrix and VMS on a VAXstation 2000
Message-ID: <8702181410.AA09488@csv.rpi.edu>
Date: Wed, 18-Feb-87 09:10:34 EST
Article-I.D.: csv.8702181410.AA09488
Posted: Wed Feb 18 09:10:34 1987
Date-Received: Thu, 19-Feb-87 19:30:40 EST
References: <8702171856.AA15847@noao.ARPA>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 29
Approved: info-vax@sri-kl.arpa
Summary: Yep, problem is Unix wants to own the primary disk

In article <8702171856.AA15847@noao.ARPA>, grandi@seismo.CSS.GOV@noao.UUCP (Steve Grandi) writes:
> In article <8702161639.AA16154@ucbvax.Berkeley.EDU> "Greg Hamm" <hamm@waks.rutgers.edu> writes:
> >
> >My query about running both Ultrix and VMS (alternately) on a single
> >Ethernetted VAXstation-2000 yielded an informative response from a DEC
> >person, which I summarize here:
> >
> I've just installed Ultrix 1.2a on a VAXstation II/GPX that has been
> running VMS for a while.  Disk DUA0 contains VMS and DUA1 contains Ultrix.
> Using the conversational bootstrap, I can boot either one and I've had no
> problems (I carefully write-protect the disk that is not in use!).  

If you're willing to physically move disks, the solution is known (and simple)
VMS can be booted from any device in the system, but Unix/Ultrix always
wants to see itself on the 0'th device.  So, put Ultrix on DUA0 and
VMS anywhere else.
	
I ran my AI VAXstation in this mode (Ultrix DUA0, VMS DUA1) for several
months.  It works fine.
	
If you run in this configuration, switching is easy. 
	1) Halt.
	2) if you want ultrix, ready DUA0.  If you want VMS, 
	   take DUA0 offline.
	3) Restart/Run
	
That's all.  Your chosen operating system will boot itself.
	
	-Bill Yerazunis