topic Re: OpenVMS as a Guest on HPVM, and Volume Shadowing. in Operating System - OpenVMS

OpenVMS as a Guest on HPVM, and Volume Shadowing.

The Brit — Thu, 07 Jul 2011 20:13:44 GMT

I seem to recall that there were some issues, or limitations, which appied to Volume Shadowing when the OpenVMS cluster nodes are Guests on HPVM.

Can anyone refresh my memory regarding this, (or reassure me that this is not the case)??

thanks

Dave.

Re: OpenVMS as a Guest on HPVM, and Volume Shadowing.

The Brit — Fri, 08 Jul 2011 12:23:46 GMT

Gentlemen (and of course, Ladies)

We have been discussing locally, the idea of OpenVMS as a Guest on HPVM, however, I seem to recall reading, or hearing, that there are certain limitations/restrictions/issues associated with Volume Shadowing and clustering, when the OpenVMS nodes are guests within HPVM’s. Can you refresh my memory, or reassure me that this is not the case.

We are currently running a 4 node cluster (3 x bl860c’s running 8.3-1H1, and 1 DS10 running Alpha 8.3). Data integrity is maintained by running Volume Shadowing and creating shadow sets with units presented from XP subsystems located in two separate data centers (5 mile separation).

As a theoretical exercise, we are examining the idea of adding a 5th node to the cluster, where this new node would be a HPVM guest. The main questions are,

If this 5th node is an OpenVMS guest instance on HPVM, will it be able to see, and mount the Cluster-wide shadow volumes, either directly, or via MSCP??
Are there any special considerations that need to be taken into account on the Guest instance.
Are there other considerations (regarding say, Clustering) which we need to be aware of

If anyone has any experience with this kind of configuration, and would be willing to share, it would be appreciated.

Thanks for any information you can provide.

Dave.

Re: OpenVMS as a Guest on HPVM, and Volume Shadowing.

G_Castel — Fri, 08 Jul 2011 16:30:17 GMT

For the tests We have done, there is no Shadow limitation ...

to cluster / shadow between Guest & non guest or alpha system you will have to use LDDriver to change the name of the disks...

Regards

Re: OpenVMS as a Guest on HPVM, and Volume Shadowing.

Volker Halle — Fri, 08 Jul 2011 16:33:22 GMT

Dave,

I seemed to remember, that an OpenVMS guest system on HPVM cannot directly acces the LUNs in the SAN. The following sentence seems to support this:

. Supports OpenVMS clusters. Data sharing in a cluster is possible using MSCP-served disk volumes

from: http://h18000.www1.hp.com/products/quickspecs/12715_div/12715_div.HTML (HPVM Overview).

Volker.

Re: OpenVMS as a Guest on HPVM, and Volume Shadowing.

The Brit — Fri, 08 Jul 2011 17:02:39 GMT

Can you give a bit more detail, or perhaps and example of how this would work?

Thanks Dave

Re: OpenVMS as a Guest on HPVM, and Volume Shadowing.

The Brit — Fri, 08 Jul 2011 17:04:09 GMT

Thanks Volker,
Your comments almost exactly match, those niggly things that were gnawing at my brain. And thanks for the link.

Dave