You are wrong - NMSQL is the older solution.

You better use NMM.

Thank you Tim.  I tried the link for the downloads, and I see the NMM 3.0 files and docs, but there is nothing under the NMM 3.0 SP1 section that I can see.  Is the NMM 3.0 SP1 maybe a hidden file?

Although NMSQL 5.2 SP2 is also supported with NetWorker Server 8.0, 8.0 SP1, 8.0 SP2, 8.0 SP3, and 8.1 versions, you are not recommanded to install it because its primary support cycle is ended. EMC now provides only extended support for it.

Bongo...wrong about what?

I'll see if we can find the latest NMM software and docs and will try that.  Even though the EMC software compatibility guide says to use NMSQL 5.4 SP 2....

You can get NMM 3 docs and installation packs on the following page (Click Documentation and Downloads):

NetWorker Module for Microsoft

And the latest NetWorker Software Compatibility Guide

Here is the picture in the latest NetWorker Software Compatibility Guide:

If you are running NW 8.1 SP1, you'd best use NMM 3.0 SP1.

Click 3.0 and you will find them. 3.0.1 is 3.0 SP1.

Configuration would be as every cluster backup is configured for NetWorker.

- create client instances for 2 physical node and the virtual node, with the SQL backup configuration on the virtual cluster.

- ensure you have SYSTEM@NODE1 and SYSTEM@NODE2 in the remote access field.

We would be curious to see if there is any recommendation from EMC on using VDI versus VSS for a SQL Server cluster. With most other backup products VSS works just fine, but if there are any limitations specific to Networker that would make it beneficial to go with VDI over VSS then that would be good to know.

There is no specific limitation to backup application. At least one EMC member already did compare these two on this list - please search for it. In summary I agree with his recommendation - use VDI as it is more flexible.