Monitoring Exadata With OEM
As you can see there is a guided Discovery path that allows us to discover all aspects of the Exadata machine and monitor it in OEM. This Level of Monitoring is not available or permitted with any other solution. If you have anotehr monitoring solution its always best to explore if you can integrate OEM with that solution rather than trying something half hearted on your own.
A Drill down View of the Compute Node . You an see that the compute nodes run Oracle Linux
Here is a complete Overview of the Exadata Discovery Process