The document provides an overview of troubleshooting techniques for Oracle 11g Real Application Clusters (RAC). It discusses proactive checks that can be performed to monitor the health of an 11g RAC environment, including verifying the status of RAC processes, the clusterware, and the automatic storage management (ASM). It also covers common 11g RAC problems such as offline clusterware resources, failed vote disks or OCR disks, and node reboot issues. Techniques for root cause analysis of problems are presented, including examining RAC log files.