Online Expert Day - HPE Data Storage - Live Now
April 24/25 - Online Expert Day - HPE Data Storage - Live Now
Read more
Operating System - OpenVMS
cancel
Showing results for 
Search instead for 
Did you mean: 

DCL quorum adjustment tool ?

Thomas Ritter
Respected Contributor

DCL quorum adjustment tool ?

Does such a tool exist ? We have a console manager running AMDS on VMS 7.3-2 which allows adjustment of quorum. Using the same VMS host, is it possible from the command line to perform the same function ?

We are losing local access to our console manager and ideally want to be able to SSH to it and adjust quorum, should the occasion arise.

Thanks.
11 REPLIES
Hoff
Honored Contributor

Re: DCL quorum adjustment tool ?

There is no DCL command-line tool.

There can be no DCL tool.

When quorum is lost, all user-level activity is explicitly blocked. This includes DCL. This is a quorum hang.

But depending on the particular Alpha boxes involved, you can use the console and the IPL C (IPC) interrupt. And this means with access into the console via terminal server or such, you can do what you want.

As was discussed elsewhere recently, you can also VPN or otherwise connect into the Windows console box and use RDP or VNC to access the PC display.

Or run the console monitor on another OpenVMS box on the same LAN as the cluster, and toss the X display around to another local box, or to a local Mac OS X box, or to a Windows box with an X server installed.

The other discussion is to add a server or add a shared I/O bus or fix the cluster hardware or reconfigure the cluster so it operates more reliably.
Hoff
Honored Contributor

Re: DCL quorum adjustment tool ?

or on re-reading your question...

SET CLUSTER /EXPECTED_VOTES

if you have not lost quorum.
Uwe Zessin
Honored Contributor

Re: DCL quorum adjustment tool ?

AMDS is a DECwindows application, right?

Can you get an X-Server on your desk and redirect the AMDS window?
.
Dave Lennon
Advisor

Re: DCL quorum adjustment tool ?

Thomas,
We also think this would be a useful tool - as you can imagine speed would be of the essense when you know the situation and are trying to continue one side of a dual site vms cluster. We also would like to be able to login to one of our standalone VMS systems and run a quick tool to do the AMDS quorum fix without having to load a X GUI.
I once asked Barry about it and he said it would seem do-able, one would need to write something to interface with RMDRIVER like AMDS does. I'm suprised this hadn't come out of the DTCS support group - I think they had a winders-based tool that would just do this.
Perhaps we can take up a collection ($$) and see if anyone would take this on?

Thanks,
Dave
Bob Blunt
Respected Contributor

Re: DCL quorum adjustment tool ?

As an alternative to a separate X-terminal on your desk you could use eXcursion (from the Pathworks 32 suite) or Hummingbird. Both are X-terminal emulators and I've used them in LAN, WAN and VPN environments successfully.

You could also run Availability Manager (the current ilk of what was AMDS) on PC. This version of the tool can be configured, with care, to use intermediate nodes as collectors and the "analyzer" runs on PC.
Wim Van den Wyngaert
Honored Contributor

Re: DCL quorum adjustment tool ?

I've seen clusters where quorum was restored by booting a cluster member with votes. It was a simple old workstation doing nothing but that.

Wim
Wim
Ian Miller.
Honored Contributor

Re: DCL quorum adjustment tool ?

The DTCS people do have something I think.

The interface to RMDRIVER is not documented.
____________________
Purely Personal Opinion
Thomas Ritter
Respected Contributor

Re: DCL quorum adjustment tool ?

Thanks for the replies. We are relocating our data centre. Our management hosts will be given remote access and staff are being placed behind firewalls. We will be getting X11 access back to our desktops, eventually. We have AMDS and DTCS. DTCS has an option for quorum adjustment. Quorum adjustment has probably been performed about 3 times in the last 10 years. The DTCS option looks like having the basis for a command line tool. It would be really nice to SSH to our management workstation using VPN and then execute something like $ adjust_quorum 'production_nodes'
John Gillings
Honored Contributor

Re: DCL quorum adjustment tool ?

Thomas,

Look at the latest version of Availability Manager.

$ prod show prod avail*
------------------------------------ ----------- ---------
PRODUCT KIT TYPE STATE
------------------------------------ ----------- ---------
HP AXPVMS AVAIL_MAN_ANA_SRVR V3.0-2 Full LP Installed
HP AXPVMS AVAIL_MAN_BASE V8.3 Full LP Installed
HP VMS AVAIL_MAN_COL V3.0-2A Full LP Installed
------------------------------------ ----------- ---------


You can run a server on a node (VMS or Windows) on the same subset as your cluster, and run a client on a PC anywhere else using certificate based authentication. You can adjust quorum from outside via the server. It also means you can have multiple clients.

Big improvement over AMDS and the older version of Availability Manager. Also far less load on the server if running OpenVMS.
A crucible of informative mistakes
Ian Miller.
Honored Contributor

Re: DCL quorum adjustment tool ?

are you up to date with DTCS software?

Do talk to that team to see what they have.
____________________
Purely Personal Opinion
Hoff
Honored Contributor

Re: DCL quorum adjustment tool ?

It is feasible and supported to cancel a quorum hang from the console via the IPL C (IPC) handler. No need for anything beyond a serial connection into the console serial line.

http://labs.hoffmanlabs.com/node/1195