If you are using Fast Recovery Area (FRA) for the archive destination and the destination is set to USE_DB_RECOVERY_FILE_DEST, you may notice that the Archive Area % Used metric does not trigger anymore. Instead you will see the Recovery Area % Used metric trigger when it hits a Warning threshold of 85% full, and Critical of 97% full. As this metric is controlled by the server side database thresholds it cannot be modified by Enterprise Manager (see MOS Note 428473.1 for more information). Thresholds of 85/97 are not sufficient for some of the larger, busier databases. This may not give you enough time to kickoff a backup and clear enough logs before the archiver hangs. If you need different thresholds, you can easily accomplish this by creating a Metric Extension (ME) and setting thresholds to your desired values. This blog will walk through an example of creating an ME to monitor archive on FRA destinations, for more information on ME’s and how they can be used, refer to the Oracle Enterprise Manager Cloud Control Administrator’s Guide.
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