 |
» |
|
|
|
Ask the Wizard Questions
License: NAS 150
The Question is:
I have a cluster of Alphstation 100 4/100's each with
a NAS150 license.
SPD 29.78.12 states:
>
> OpenVMS Cluster Client Software
>
> VMScluster configurations can be configured with CPUs that operate and
> are licensed explicitly as client systems. OpenVMS Cluster Client li-
> censing is provided as part of the Digital NAS150 layered product
> package. OpenVMS Cluster Client CPUs contain full VMScluster
> functionality as described in this SPD, with the following exceptions:
>
> o Client CPUs cannot provide votes toward the operation of the
> VMScluster system.
>
> o Client CPUs cannot MSCP serve disks or TMSCP serve tapes.
>
Am I to assume that a cluster member with a NAS150
license should not be able to serve it's local disk to
the rest of the cluster, or is the Client Software just
a subset of the VAXcluster software which can be installed
if required.
The SPD is not clear on this.
In practice I have been able to serve out these disks,
should I have been able to do this?
Hope you can make the situation more clear,
The Answer is:
The Client license provided as part of NAS150 is a subset of the 'full'
clustering license. From a legal 'terms and conditions' viewpoint the license
does not permit the node to Vote or T/MSCP serve disks and tapes. From a code
viewpoint the Ts and Cs are not enforced, so, as you have found, it is quite
possible to Vote and serve.
We are still struggling with how best to provide Cluster licensing. The 'full'
license is priced on the assumption that the node is a server, and so
unreasonably expensive for workstation satellite 'client' nodes. Hence the
introduction of the Client concept in NAS150. However, feedback from customers
tells us that we've still not got it quite right.
Our current plan is to change the Client so that it permits T/MSCP serving, but
continues to disallow voting. In V7.1 we intend to enforce the 'no voting'
restriction in the code. The Client will also be separately purchasable (not
part of NAS150). I can't promise this will happen (we're still working some of
the finer details), but it's highly probable.
The wrinkle is that every cluster needs a Vote to run, which means that every
cluster needs a node with a 'full' (expensive) license. And if you need
continued operation when the server node goes down, you need two voting nodes.
From an historical pricing perspective this isn't cheap - but it's still less
than cluster software from other vendors.
Does this clear things up at all? Let me know if you need any further
information or clarification. I'm sorry the SPD isn't clear. I'll try to fix it
in the next update.
|
