Oracle Database Tips by Donald Burleson

Oracle10g Grid Computing with RAC
Chapter 8 - RAC Administration

Using Enterprise Manager

For RAC systems like HP TruCluster and PolyServe Matrix Server-based Linux RAC, it is possible to use the Context Dependent Symbolic Link (CDSL) facility to separate the $ORACLE_HOME/network directory from the shared Oracle Home installation without having to physically install the Intelligent Agent on each node in the cluster. This employs using a specific keyword in the filename (or a symbolic link) that distinguishes the name of the current member node of the cluster.

• Beginning with version 9.2.x, the Intelligent Agent can store the binary state files (*.q) into an alternate directory rather than use the hard-coded $ORACLE_HOME/network/agent directory. This functionality is very similar to the CDSL method listed in option 2 above.

To force the agent to read and write the binary state files to/from an alternate location, the environment variable ora_oemagent_dir must be set prior to starting the agent. For example, the following would force the agent to read and write its state files to the /usr/oracle/agent directory:

export ORA_OEMAGENT_DIR=/usr/oracle/agent
agentctl start

For more details and updates, please refer to the Oracle MOSC Note (158295.1).