I came into work on Monday and saw that all of the databases which are running on our development database server were no longer reporting to our Oracle Grid Control. After looking at the Grid Control server, I realized that the management agent was not functioning correctly. Time to investigate...
I went to the command line and issued the following:
emctl status agent
Everything looked fine, but then I realized that the "Collection Status" indicated that it had been disabled by the collection manager. In my case, this had occurred because over the weekend I had been moving some files around and filled up one of the disks on the server completely. Realizing I had done so, I immediately removed some of those files to free up disk space. Unfortunately, this disk which filled up was the same one on which the Oracle Management Agent is installed. Being that the disk filled up and that the collection manager was not able to add the required XML files to disk, it immediately disabled itself.
The remedy: Of course, ensure that the disk has available space. Once you've done so, simply restart the management agent. It will begin working immediately.