I could see most of the server are reporting double in UIM ,One host from robot and other from vmware probe.
In some cases during monthly patches the server will be rebooted ,in that case for few server tools may not start and vmware probe is creating new entry for the vm,once tools starts again the device correlation is not happening .By anyway it can be avoided. Again I need to delete the cs_key of the server.
For some third party OVA template and appliance VMtools will not be there ,in this case how it can be overcome ?
What are the key things where server discovered from robot and server discovered from vmware must be same (ip,hostname,mac,origin)for this device merging.
This is a "common" situation with discovery server. You can use the python rules in discovery server to limit that or tune discovery server a bit to reduce this. The other thing is potentially use qos_processor to drive the reconciliation through discovery_server. Other DB manipulations could also help a bit in case any other solution fit the need but should be driven by CA Services.
Can you tell some uses cases of python rules and other fine running which should resolve this?
Which version of discovery_server probe in use ?
Discovery Server 8.50 and UIM version is 8.5.
Is <vm_id> device correlation rule (defined in discovery_server.cfg) active or not ?
The rule uses guest machine's UUID (vm id) as primary correlation driver - so additional device entry will never be spawned as long as guest machine's ID remains the same.
vm_id is enabled as true