The DBO Flashback Percentage Used rule/alarm in Foglight is activated when the percentage of space used in the Oracle Flash Recovery Area (FRA), also known as `db_recovery_file_dest`, exceeds a set threshold (commonly 75%). The FRA is a special storage area managed by Oracle for backup, archive logs, and flashback logs. When the FRA gets full, Oracle may start purging old flashback logs, and critical operations (like archive log writes) can fail or cause the database to hang until space is made available.
This alarm monitors the total used space in the FRA. If your database is configured to store archive logs in the FRA, a rapid increase in log generation or insufficient FRA size may quickly push usage above the threshold. When the FRA fills up:
If archive logs are written to a different destination (not the FRA), this alarm will not cover those locations, you must monitor those paths separately.
If archive logs are stored in the FRA:
Treat this alarm as urgent. Free up space by deleting unnecessary files, backing up and removing old logs, or increasing the FRA size. This prevents the database from hanging and avoids potential data loss.
If archive logs are NOT stored in the FRA:
This alarm will not alert you about issues elsewhere. Set up monitoring for your actual archive log destination.
Best Practices:
Example:
If your FRA is 80% full and your archive logs are stored there, the DBO Flashback Percentage Used alarm will warn you before your system hangs or loses recoverability. If your archive logs are stored outside the FRA (such as on a NAS or ASM group), you must monitor that location with a separate alarm.
