Just like everything else in Enterprise Manager, an Exadata is a target and all of its components are targets. All of these pieces can be removed through the 12c console.
Select Exadata from the bottom of the main Targets drop-down to display a list of Database Machines in your environment. Highlight the row containing the subject machine and press the Big Red X to take you into the detail page.
The left panel shows you the individual components effected by this change. Leave that panel highlighted at the DB Machine level to remove everything.
The right-hand panel is quite straight-forward. The default action is to Remove all members of the Oracle Exadata Machine. You can also select individual components for removal from this screen.
Check the box to Unsubscribe SNMP subscriptions if you have any configured.
Set the credentials for both the Storage Server and Infiniband Switch. Both of them will require root.
That’s all there is to it. Remember that metrics are gathered and stored in your OMR repository database for each of those targets, so the target removal transactions can take a while to process. For instance, the machines I removed had been in production for over four years and target removal on a hefty OMR database took about thirty minutes each.
This is kind of a rare event, so I thought I’d share it with you.