Even after enabling alarms/QoS for a specific metric in the VMware probe, those metrics are not being collected, and alarms not being generated.
The problem may not affect all metrics; in particular, Disk Free/Capacity metrics seem most likely to be problematic.
If everything is configured properly from the UIM side, and the template has been applied, metrics show active, etc, the problem is most likely with VMWare Tools. Many customers have reported problems with older versions of VMTools and the probe will not be able to retrieve all metrics if VMTools is not installed.
Install/upgrade the latest available VMware Tools onto the guest VMs. If the latest version is already present, try re-installing VMTools.