About the *.png. IIRC earlier(current?) behaviour is that if a VM crashed and the VM Monitoring for VM was active it creates a Screenshot if the crash occures. Yes you can also create a screenshot with the help of the APIs.
When investigating older or long living vSphere environments they leave all kind of waste behind.
- Admins removed VMs/vDisk from inventory instead deleting
- Abortet svMotions
- VM Helper Snapshots
- vRanger Replication VMs leave some weird files behind
- Rescue Operations on the Snapshot chains
- and so on
Does RVtools comes with a feature to list non active vDisk? It lists VMs in the Healthtab for sure.
Otherwise you can run some find, grep on every *.vmx to to find a reference to your *.vmdk. But most likely you can remove it.
Regards,
Joerg