The Enterprise Manager Cloud Control’s Overview of Incidents and Problems section identified ‘Metrics Global Cache Blocks Lost at XXX’ for a relatively new database, suggesting a potential network issue likely related to the private network interfaces.Troubleshooting was guided by My Oracle Support documents, which outline common causes and initial diagnostic steps.

Further actions included making adjustments across nearly all OSI Model Layers—such as enabling jumbo frames, tuning NIC buffers, adjusting IP fragmentation parameters, optimizing socket buffers, and refining the database layer. These measures collectively reduced ‘gc block lost’ events to nearly zero.