Oracle Enterprise Manager monitors all targets and has the ability to alert administrators when an issue occurs. For example when a host or a database is down an alert is created and additional notification can be triggered.
In essence this is a great solution, however in cases where you do for example maintenance you do not want Oracle Enterprise Manager to send out an alert as you intentionally bring down some components or create a situation which might trigger an alert. For this Oracle provides you the ability to create a blackout from both the graphical user interface as well as the CLI. A blackout will prevent alerts to be send out and you can do your maintenance (as an example).
One of the things you will have to provide during the creation of a blackout is the blackout reason which is a pre-set description of the blackout. This is next to a free text description. The blackout reason will provide you to report on blackouts in a more efficient manner.
Oracle provides a number of blackout reasons, however your organisation might require other blackout reasons specific to your situation. When using the CLI you can query all the blackout reasons and you can also create new blackout reasons.
To get an overview of all blackout reasons that have been defined in your Oracle Enterprise Manager instance you can execute the following command to get an overview:
In case the default set of blackout reasons are not providing you the blackout reason you do require you can create your own custom blackout reason. When using the CLI you can execute the following command:
emcli add_blackout_reason -name="
As an example, if you need a reason which is named "DOWNTIME monthly cold backup" you should execute the following command which will ensure that next time you execute get_blackout_reasons you should see this new reason in the list. It also ensures it is directly available in the GUI version when creating a blackout.
emcli add_blackout_reason -name="DOWNTIME monthly cold backup"