Steps - Blackout OS level

--.>To know blockout status:

. oemagent  (connecting to oem env file)

>emctl status blackout

---> complete server blackout

. oemagent

>emctl start blackout "maintenance" -nodelevel    ----> To start blackout

-- emctl stop blackout "maintenance"   ----> To stop blackout

maintenance --- Blackout name

-->To know the perticular db is configured or not in OEM

. oemagent

>emctl config agent listtargets

[xxxx, oracle_database]

....

....

-->To start perticular database blackout

>emctl start blackout "<name>" xxxx:oracle_database  ### to start blackout

>emctl status blackout "<name>"

--> To stop blackout

> emctl stop blackout "<name>"