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Alpha server/workstation clustering

 
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David1 Sperduto
Occasional Visitor

Alpha server/workstation clustering

This seems to be the closest category for this question. If someone can suggest a better place for me to post this, by all means shout it out.

I managed a Microvax II with VMS v. 6.x for over a decade. It ran up to 4 or 5 terminals, including some PCs emulating via Kermit. Now I want to get a new machine (long story) and am thinking maybe an Alpha station or server, but I guess I am a one-trick pony. I never learned anything about anything but this one MV.

Now I am at a loss as to how I will run more than one terminal from an Alpha. I notice that even the servers seem to have no more than 1 or 2 comm ports. Do I need some kind of external network box to run 2 or 3 terminals?

I know this is a very basic question, but if anyone can at least point me to some learning resources, I would be grateful.

The Alphas I am looking at include possibly a CS20 (API), DEC 1000A server, Dec PWS 600AU, or Microway Alpha Server DS20E.

Thanks for whatever help you can offer,

David
10 REPLIES
Volker Halle
Honored Contributor

Re: Alpha server/workstation clustering

David,

welcome to the OpenVMS ITRC forum.

Nowadays, serial line terminals have mostly been replaced by PCs running terminal emulators and connecting via TCPIP (TELNET) to the VMS system.

You can still add serial line interfaces (PBXDA) into Alpha systems. Or you could use a DECserver to connect your terminals and have them talk to the VAX/Alpha via LAT or TELNET.

You could also 'emulate' your VAX on a PC (using CHARON-VAX or simh) and add serial interfaces to the PC and use them by the emulated VAX.

Volker.
Hoff
Honored Contributor
Solution

Re: Alpha server/workstation clustering

Volker has a number of very good points.

If you're looking at Alpha, boxes such as the AlphaServer DS10L and other EV6-class boxes are available for little money.

I'd personally tend to pick other boxes in place of the first three boxes for various reasons, and the AlphaServer DS20e is probably more capable than you need. The aforementioned AlphaServer DS10L has a single PCI slot in a 1U rack-mount box, but it's massively faster than your MicroVAX II -- and a DECserver or thin clients or terminal emulators will provides your access needs without using the PCI slot.

In addition to VAX emulation, I'd take a long and careful look at a recent (used) MicroVAX 3100 series or VAXstation 4000 box, as well. This would minimize the need to find applications and such, or to translate existing applications. VAX 4000 and up are (also) more than you need, and some of these are far bigger than you likely want.

I've posted an OpenVMS hardware introduction with various additional links to local pages on VAX, Alpha and Integrity, starting here: http://64.223.189.234/node/6

Stephen Hoffman
HoffmanLabs.com
Steven Schweda
Honored Contributor

Re: Alpha server/workstation clustering

I'd vote for a (cheap DECserver) terminal
server, if you really need serial ports. If
full modem control is not required, a 90TL
(or better) should be good enough.

Support for the newest (supported) graphics
cards is limited to EV6 (or newer) systems,
so I'd tend to avoid systems as old as that
1000A or the PWS. Actual performance is
another reason to prefer EV6, although when
compared to a mu-VAX II, it's hard to find
even another VAX that slow. (Does the CS20
do VMS?) My preference for small/fast/cheap
is the XP1000 (unless you expect to use fibre
channel storage, because its SRM firmware
lacks a wwidmgr, and it's not likely ever to
change). A DS20E (or equivalent) would be
nice, but it'd seem to exceed my budget.
David1 Sperduto
Occasional Visitor

Re: Alpha server/workstation clustering

Wow. Thank you all for the replies.

To tell you the truth, I've got a little studying to do about DECservers, TELNET, 3100s, and everything else you mentioned. Thank you, Stephen for the link. It looks like it will be very helpful, because I am at the beginning of a learning curve.

Your help is especially welcome because in most business circles here, somebody that likes VAXen and VMS can feel very lonely. The muVax I was running all those years is now under control of another group and they do not appreciate its speed, stability, reliability and independence from Microsoft version changes.

Your recommendations for appropriate hardware is appreciated, too, since I was having a hard time figuring out what machines were more power than I need.

That's a good question about whether the CS20 would do VMS, Steven. I was wondering that, too. And knowing the EV6 is the lowest graphic-capable chip helps, because I do want graphics capability.

I guess my only question for now is, if I use a DECserver to handle the terminals and it talks to the VAX/Alpha, where do I configure the terminals (TXA0, TXA1, etc.). Is that an integral part of OpenVMS on an Alphaserver, just as it was on the muVax? Or are the terminals cofigured on the DECserver and merely identified on the Alpha?

Thanks again,
David
Steven Schweda
Honored Contributor

Re: Alpha server/workstation clustering

> [...] they do not appreciate its speed [...]

Speed? It has no speed. What's to
appreciate?

> [...] knowing the EV6 is the lowest
> graphic-capable chip helps, because I do
> want graphics capability.

Well, not exactly. Even an EV4 system (like,
say, a 1995-vintage AlphaStation 200 4/233)
can do graphics (with, say, an ELSA GLoria
Synergy-8 card, as well as a bunch of older,
harder to find DEC cards), but the device
drivers for the newer cards (like the ATI
Radeon 7500) require EV6.

> [...] if I use a DECserver [...]

Configuration requirements depend on what you
want to do with the serial ports. For simple
interactive remote log-in, you just need to
configure LAT or Telnet on the VMS system,
and (probably) teach the users the extra
(few) steps needed to log in from the
terminal server instead of a directly
connected serial port.

If you're connecting from an application on
the VMS system to some device on a serial
port, it's a little more involved, and I
don't generally do it, but I believe that you
can configure a terminal server port for
remote access. Without actually reading
things, I'd guess that LATCP CREATE PORT and
SET PORT would be the things you'd need to
let you use a terminal server port as you
would a local serial port.

http://h71000.www7.hp.com/doc/83final/6048/6048pro_039.html#latcp_part

If you had TXA0, TXA1, et c. hard-coded into
applications, you'd probably need to define
logical names to redirect those names to
LTAxxx, but that might be all you'd need to
cope with that extra annoyance.

Depending on what you want to do, you can
also create a SERVICE for a port on the
terminal server, and connect to that service
from any system. For example, I have a modem
on one here, and I can use "SET HOST /LAT
service_name" to talk to it:

alp $ set host /lat modem
%LAT-S-CONNECTED, session to MODEM on node SP2 established
atAT-I-TODISCON, type ^\ to disconnect the session
OK

(The modem's non-DEC carriage control put the
"at" command on top of a message, but after
that it's normal.)

So, depending on details, you might be able
to do all the configuration on the terminal
server, or you might need to do some at each
end. Many things are possible.
Hoff
Honored Contributor

Re: Alpha server/workstation clustering

>>>if I use a DECserver to handle the terminals and it talks to the VAX/Alpha, where do I configure the terminals (TXA0, TXA1, etc.).<<<

LAT$SYSTARTUP.COM and SYSTARTUP_VMS.COM are the two relevant procedures for setting up LAT terminal devices.

>>>Is that an integral part of OpenVMS on an Alphaserver, just as it was on the muVax? Or are the terminals cofigured on the DECserver and merely identified on the Alpha?<<<

LAT is an integral part of OpenVMS; your own current MicroVAX has LAT capabilities, and most any OpenVMS release and most any DECserver has LAT support.

I'll post up an intro to LAT later today; a new node on this topic over at the same new web site. Set-up intro, whether or not modem control is needed (and it's used for more than just modems), etc. There are already DECserver MOP topic nodes posted.

The AlphaServer DS20L and the API CS20 probably won't boot OpenVMS, but -- even if you or somebody you have hired can manage it, it's not a standard and officially supported AlphaServer for OpenVMS there will always be questions.

And like the AlphaServer DS20e I mentioned earlier, the CS20-class box is likely more power than you need here.

Stephen Hoffman
HoffmanLabs.com
Robert Gezelter
Honored Contributor

Re: Alpha server/workstation clustering

David,

Others have posted extremely good information, and I will only offer a few clarifications.

Insofar as access from outside into an Alpha. A question that you do not mention is whether or not you have or intend to have, an IP stack on your Alpha system. If you have an IP stack, then connections using telnet over the Ethernet are a viable option. If you do not, then LAT is needed (or direct hardware serial ports, as was mentioned). Terminal servers are available on the used and new market from a variety of vendors.

On the subject of graphics, I can vouch that EV4 systems (e.g., the AlphaStation 200 4/266 sitting on one of my desks) certainly run graphics, just not perhaps the latest generation. If your graphics requirements are the MOTIF-based DECwindows desktop, it certainly runs quite well. There is also always the option of using an external X-windows display.

Also, if you do not anticipate having the funding to bring up a cluster, it is often forgotten that one can create access to a DECnet nodes files through a combination of proxies and logical names.

I hope the preceding is helpful.

- Bob Gezelter, http://www.rlgsc.com
David1 Sperduto
Occasional Visitor

Re: Alpha server/workstation clustering


I am getting the message that DS20 or CS20 are a wrong turn for me, if only because VMS is not commonly used on them.

But also, from what the Wikipedia article says about DECservers, none ran VMS. Is that still a limitation? Would I have to run UNIX on the DECserver? I am UNIX-ignorant and I don't want to learn another op system if I can avoid it. I might prefer to network several VAXstations or Alphastations together. Is it possible to run an application on, say, two Alpha stations, and have a common database (used by both stations) on one station? I would think yes.

That is a great link to the LATCP utility, Steven. Thank you.

I think I lean away from VMS emulation on a PC too, because then I have complications when the PC changes OS versions (or at least this is my feeling). One reason I liked the microVAX is because it was independent of Windows issues - from 1987 to 2007 it just kept running, with minimal disruption for VMS upgrades ( and one self-induced crash, when I accidently deleted system files - ouch!!!). The machine still is part of a company supporting large construction engineering and surveying.

I have to assume, Steven S., that my perception of speed in the microVAX II was misplaced, since my experience is very narrow! So I guess I can look forward to dizzying experience with a newer VAX or alpha. Even so, my Windows applications on PCs would crash, bog down or frustrate me on a daily basis. For computational software (most of what we did), the instantaneous and reliable performance of the MicroVAX was a good thing. And if necessary, the VMS operating system, with DEC language, was transparent enough that I could debug problems or write my own command routines. Forget about that in Windows!

I am not using graphics now on the MicroVAX, although, incredibly, we did have an application with graphics for a couple of years. THAT was when the VAX bogged down to a standstill! Maybe that's what you're talking about, Steven. It would take a half-hour to regen the screen!

Or maybe it's just what I'm familiar with.

I'll have to find out from my application supplier what kind of requirements his graphics have. And whether the EV6 system would be an added speed advantage, even if the EV4 could handle the application.
It's actually a minor question, since I may decide the graphics option is not of interest to me. Computational software is the main interest.

Ok, so I have some studying to do. I realize some of this is just learning the acronyms, but this is my syllabus:

TCPIP (TELNET) and Ethernet (although I lean away from terminal emulators and towards PCs running Kermit, conx via the Comm port) I do remember reading about Ethernet in the Microvax manual, but never learned about it since I had a stand-alone machine.

PBXDA serial line interfaces

DECserver to vax/alpha via LAT or TELNET

PCI slot

IP stack

look at microVAX 3100
VAXstation 4000
XP1000

Obviously, I have some studying to do and will probably be back with more questions after class.

Thanks again for all your help.

David
Steven Schweda
Honored Contributor

Re: Alpha server/workstation clustering

> [..] DS20 or CS20 are a wrong turn [...]

A DS20E is a nice system, and runs VMS, but
its cost beats my budget. (I lean toward
cheap junk.)

> [...] DECservers, none ran VMS. [...]

They run some special DECserver software, not
VMS or any UNIX, but they can work with VMS
and UNIX (with some fine print). They have
their own built-in HELP, too.

> Is it possible to run an application on,
> say, two Alpha stations, and have a common
> database (used by both stations) on one
> station? I would think yes.

A VMScluster would normally be the foundation
of such a system, and can include VAX, Alpha,
and/or IA64 systems. Shared storage can be
arranged in a few different ways. Details
depend on your actual requirements (as with
all this stuff).

> [...] I can look forward to dizzying
> experience [...]

Probably, but it depends on what you're
doing. if a mu-VAX II from 1986 looks perky
when it does what you ask it to do, then a
fancy new system may not be much more
impressive. (You can't get much faster than
right away.)

> [...] I do remember reading about Ethernet
> [...]

You _could_ put a DELQA into your mu-VAX II,
and have all the fun of an old, slow Ethernet
interface in your old, slow mu-VAX II.
David1 Sperduto
Occasional Visitor

Re: Alpha server/workstation clustering

OK, thanks Steven, that clarifies a little more about the capabilities/scale of the DS20E, and the DECservers. Very glad to hear I wouldn't have to get into UNIX (no offense meant to its advocates).

That bit about VMSclusters seems to put things in focus, too. It is good to know it can include both VAX and Alpha systems, and that it is the "normal" setup and can include shared storage. Even if I have to do a lot of reading, trial and error, at least I know my goal is a standard one and not a wild idea.

For now, I have just acquired an Alphaserver 1000A (despite its limitations re: graphics) because it will (I hope!) allow me to at least run the application I want on one "node". That seemed best considering I have some studying to do before buying two or three pieces of equipment for a cluster.

Also, the 1000A was CHEAP in my book, and I cannot resist a bargain!

>>You _could_ put a DELQA into your mu-VAX II,
and have all the fun of an old, slow Ethernet
interface in your old, slow mu-VAX II.

You know, that's an amusing idea, but maybe I will revise my notion of fun!

Thank you for your suggestions. This forum has been a great help.

David