Question: Can the CMDB task "Merge Duplicate Computers" be used to merge both Computer and Virtual Machine resource types, such as for the purpose of merging based on Serial Number?
Answer: The general answer to this is no*, the Merge Duplicate Computers task cannot merge Computers and Virtual Machines. This is because these are two different resource types and have related but also different data classes. This answer applies to all CMDB merges, which include manual, Merge Duplicate Computers and also Resource Merge Rule.
As there is no method to combine dissimilar resource types, the customer would need to decide which to keep and then delete the unwanted one, or, provide some method for copying over one's data classes to the other, then deleting the unwanted one.
If there are duplicate data classes that need to be cleaned up, such as duplicate Serial Numbers, a bigger issue is present. There is no method out of box to create duplicate Serial Numbers, for example, therefore most likely incorrect workflow processes were used to accidentally create this issue, such as reusing computers or their name or deploying images with a Symantec Management Agent already integrated with the Symantec Management Platform. The customer would then need to resolve the bigger issues for the end result, duplicate Serial Numbers, to ultimately be completely cleaned up.
* In some versions of 7.1, this was possible but only due to a defect. This has been resolved and merges once again no longer enable Computers and Virtual Machines from being merged in 7.5.