Month: September 2024
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Oracle ACFS File System: Inode Limitations Explained
This content discusses an issue with running out of inodes on a directory in the ACFS (Oracle Automatic Storage Management Cluster File System) file system after a large table export. Generally, even with sufficient disk space, a high number of small files can exhaust available inodes, prompting alerts. In this case, we have seen that ACFS doesn’t have a pre-allocated inode table; rather, it estimates inodes based on available space, leading to confusion during inode checks.
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Troubleshooting gc cr/current block lost events and Improving Oracle RAC Network Performance
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, and optimizing socket buffers as well as refining the database layer. These measures collectively reduced ‘gc block lost’ events to nearly zero.
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Resolving Enq: TX – Row Lock Contention with Real-life Scenario Analysis
When encountering the Enq: TX – row lock contention wait event, it’s crucial to identify the root cause before taking action. This contention arises when multiple sessions attempt to modify the same row in a table simultaneously. To resolve it, database administrators should pinpoint the blocking session and sql statement. A detailed analysis of specific SQL statements can provide valuable insights for the development team, facilitating faster resolution.
Osman’s DBlog 