EM 12c/13c Send Email Notification When OMS or Repository Database Down

In Oracle Enterprise Manager 12c/13c deployment, normally the OMS is responsible for sending all metric alert notifications, but in cases where the OMS or repository database is down, it is not able to do this. Therefore,  the Out of Band email notification is introduced as a backup mechanism for sending email notification when the OMS or repository database itself is down.

EM 13c Agent is unreachable as its first severity has not yet come after blackout end

The agent status shows "Agent Unreachable (Post Blackout)" in Oracle Enterprise Manager 13c console. On the agent home page, it shows following error message,

  Agent is unreachable as its first severity has not yet come after blackout end.

It is seen in EM 13c, can can be fixed by running following commands on agent host,

  ${AGENT_INST_HOME}/bin/emctl stop agent

  ${AGENT_INST_HOME}/bin/emctl  clearstate agent

  ${AGENT_INST_HOME}/bin/emctl start agent

RMAN left defunct server processes and NetBackup nborautil processes

RMAN jobs can successfully backup database to tape with NetBackup, but leave server processes (RMAN channels) and NetBackup nborautil processes running. The processes look like defunct processes.

Mount DVD/CDROM with command on Linux CentOS / Red Hat / Oracle Linux / Ubuntu

 Minimal install is an important security for deploying Linux. It means only essential packages are installed. Therefore, GUI is usually not available. It becomes helpful to know how to mount CDROM/DVD when you need to install packages/software from DVD.

Oracle 19c Installation on Red Had Enterprise Linux 8 / Oracle Linux 8 – [INS-08101] Unexpected error while executing the action at state: ‘supportedOSCheck’

When installing Oracle 19c Grid Infrastructure (GI) or 19c Database (runInstaller), got following error,

[INS-08101] Unexpected error while executing the action at state: 'supportedOSCheck'

Error details,

Cause - No additional information available.

Action - Cantact Oracle Spport Services or refer to the software manual.

Summary
 - java.lang.NullPointerException

Use oradebug To List All Internal Events Set In Oracle Database

Oracle internal events can be set at both sesson level and system level as following,