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From: garry@batcomputer.UUCP
Newsgroups: comp.os.vms
Subject: Re: Backups and disks
Message-ID: <1650@batcomputer.tn.cornell.edu>
Date: Wed, 8-Jul-87 23:52:59 EDT
Article-I.D.: batcompu.1650
Posted: Wed Jul  8 23:52:59 1987
Date-Received: Sat, 11-Jul-87 17:58:28 EDT
Reply-To: garry@oak.cadif.cornell.edu
Organization: Cornell Engineering && Flying Moose Graphics
Lines: 26

In a recent article RMALOUF@SBCCMAIL.BITNET (Rob Malouf) wrote:
>...  However, I noticed in the documentation that an RA81
>disk drive can be driven by two UDA50 controllers.  If this is really true,
>then I could connect the 11/730's RA81 to controllers in both machines.
>This kind of dual-porting would create a shared disk drive and a "poor-man's"
>VAXcluster!  All my instincts say that it could never work...

A shared disk drive does not a Vaxcluster make. The only reason people
dual-port disks on VMS, I think, is so that they can be manually switched
(without having to move cables) over to machine B if machine A goes down.

More seriously, Dec says you can't plug an RA81 into a microVax (at least
our uVax's) at all - seems Dec screwed up such that the necessary cabling 
would break FCC rules. I assume that that means there would be "too much"
RF leaking out of the cabinet.

As a result of this, we are in the process of throwing away our RA81's and -
after years of loyalty - buying non-Dec disk drives.

garry wiegand   (garry@oak.cadif.cornell.edu - ARPA)
		(garry@crnlthry - BITNET)

PS - if you *do* have a dual-ported disk it might be a fun exercise to
   persuade VMS that it's "actually" an Ethernet... no technical reason
   why it couldn't be done.  Performance from the "remote" node would
   be terrible though.