How To Fix VIRT339 - Max. Unreferenced Interval Count

SAP Error Message - Details

• Message type: E = Error

• Message class: VIRT - Virtualization Monitoring

• Message number: 339

• Message text: Max. Unreferenced Interval Count

Max. Unreferenced Interval Count
The average high unreferenced interval count (UIC) is an indicator of
central storage contention. A low UIC count indicates that storage
contention is high and you might experience storage problems. (Maximum
value within the last collection interval)

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message VIRT339 - Max. Unreferenced Interval Count ?

  The SAP error message VIRT339, which states "Max. Unreferenced Interval Count," typically occurs in the context of SAP's Virtual Memory Management. This error indicates that the system has reached the maximum number of unreferenced intervals that can be handled by the memory management system. This can lead to performance issues or even system crashes if not addressed.
  Cause:
  
  Memory Configuration: The system may not be configured optimally for the workload, leading to excessive unreferenced intervals.
  High Workload: A sudden increase in workload or data processing can lead to a spike in memory usage, causing the system to hit the limit.
  Memory Leaks: There may be memory leaks in the application or in the SAP kernel, which can lead to unreferenced intervals accumulating over time.
  Improper Cleanup: The system may not be properly cleaning up unreferenced intervals, leading to an overflow.
  
  Solution:
  
  Increase the Limit: If possible, increase the maximum unreferenced interval count in the system configuration. This can often be done in the SAP kernel parameters.
  Optimize Memory Usage: Review and optimize the memory usage of your applications. This may involve tuning specific transactions or processes that are consuming excessive memory.
  Monitor Workload: Use SAP monitoring tools to analyze the workload and identify any spikes or patterns that lead to the error. This can help in planning for capacity or scaling resources.
  Patch and Update: Ensure that your SAP system is up to date with the latest patches and updates, as these may contain fixes for memory management issues.
  Check for Memory Leaks: Use tools to analyze memory usage and identify any potential memory leaks in your applications or the SAP kernel.
  Restart the System: In some cases, a system restart may temporarily alleviate the issue, but it is not a long-term solution.
  
  Related Information:
  
  SAP Notes: Check SAP Notes related to VIRT339 for specific guidance and recommendations from SAP support.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they have found.
  System Monitoring: Utilize transaction codes like ST02 (Tune Summary) and ST03 (Workload Analysis) to monitor memory usage and performance metrics.
  Kernel Parameters: Familiarize yourself with relevant kernel parameters that control memory management, such as rdisp/PG_SHM and rdisp/PG_MAX.
  
  If the problem persists after trying the above solutions, it may be necessary to consult with SAP support for further assistance.