In this case I will describe how to create an alert definition based on a self created symptom in vROPS. In this example I want to monitor snapshots on VM’s which are older then 3 days. To achieve this I first have to create a symptom.
Go to Alerts/Symptom Definitions/Add symptom definition:

In the field “Base Object Type” select vCenter Adapter\Virtual Machine. Then select “Properties” and “Disk Space\Snapshot\Age (Days)”

Now it’s time to configure the symptom:
- Give the sympton a name
- Select info, warning, immediate or critical
- Determine the treshold
- Determin the Wait Cycle (each Wait Cycle is 5 minutes)

Save the symptom.
After creation of the symptom I can create an Alert Definition.

Give the Alert Definition a name:

Select the Base Object Type:

Select the Alert Impact:

Drag the symptom that I created earlier (Snapshot > 3 days) to the right and save the Alert Defintion.

Depending on the wait cycle that is selected the Alert wil appear as shown below:
