DEQNA and VMS 5, was Re: MicroVax II

[Steven M Jones]

On 07/29/2016 19:30, Jerry Weiss wrote:
>
> Note that DEQNA will not work (at all) on either version. 
> You’ll need a DELQA.

On 07/30/2016 08:50, Paul Koning wrote:
> 
> Yes, VMS stopped supporting the QNA at some point because, even
> after 12 ECOs, it could not be made to work properly.  If I
> remember right, the issues showed up mostly in clusters; DECnet
> didn't mind so much.


The DEQNA was deprecated and for good reason, though you could still use
it with many if not most versions of VMS 5.x. And as Paul points out if
you're using it for lighter duty, or if it's all you've got, you might
as well give it a shot.

I was working at MIT in '90-91 and one of the labs (LIDS, I believe) had
a cluster of VAXstation 2000s being served by a MicroVAX II. The
VAXstations may have had a small local disk, but they were all clustered
with if not booting from the MVII.

The MVII had a DEQNA, which I discovered meant that when I was doing
I-forget-what for them and brought the cluster back up, I had to
sequence the booting of the VAXstations. If I booted two of them too
close together, the MVII would crash.

But it did work, if you'll accept that caveat as "working," and by that
time if they were still running (Micro)VMS 4.x it would have stood out.

I'm sure I did tell them to get a DELQA, preferably a DELQA-YM, but many
of the labs I supported were running on a shoestring, and indentured
graduate students to reboot as needed were often cheaper than new
hardware...

--S.