Certainly, you can do this with nworks!
if you want to disable VM discovery only for certain specific Hosts - then that can be done in the SCOM UI.
You can disable discovery per-host (or create a dynamic group of hosts, and disable that way)
Best to override two discovery rules -
1. Rule 'nworks Stage 3 - virtual machine Containers discovery' (discovers VM Containers, our topology objects that hold VMs)
2. Rule 'nworks Stage 4 - virtual machine discovery' (discovers the VMs themselves)
Here's how to disable VM discovery :
In the SCOM Console, Authoring section, Discoveries, remove any Scope and search for nworks. You'll see various rules including Stage 1 - 4 rules.
Note for Stage 3 rule the target is ESX Server, this discovers the Root VM Container under each Host. You can override for one Host, or a Group of Hosts.
For Stage 4 rule the target is 'VM' which actually is the child VM Containers. These containers have host name as a property, so you know which host you are targeting. LIkewise you can use that hostName property to populate a Group of VM Containers, and use that for your override if desired.
Right-click each Rule and override (for specific object, or for a group) and check the disable box. As always, such overrides should be stored in your own MP dedicated to nworks MP overrides - not in the Default MP. Note - do not choose 'Disable the object discovery' from the right-click context menu - this will store the override in Default MP! Instead choose Override in context menu, then in the dialog check the Disable checkbox, and choose destination MP.
Once this override is pushed to all agents on Collectors, then they will not discover or update VMs for those Hosts.
Note - If those VMs have ALREADY been discovered - this will not remove them. This is a SCOM issue, where disabling a discovery rule does not remove already-discovered objects. In order to remove existing VMs, there is a powershell command -removeDisabledMonitoringObject - good blog post from Jon Almquist on this here http://blogs.technet.com/b/jonathanalmq ... bject.aspx
Any questions let me know!