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AEM error logs show warnings related to inability to delete Lucene files from MMapDirectory

Last update: Sat Nov 01 2025 00:00:00 GMT+0000 (Coordinated Universal Time)

Warning messages in Adobe Experience Manager (AEM) logs indicate that Lucene files can’t be deleted from MMapDirectory. These warnings appear during reindexing while AEM is running, leaving the index cache in an inconsistent state, thus impacting system performance or behavior. To fix this, stop the AEM instance, clear the affected cache folders, and restart the system.

Description description

Environment

  • Adobe Experience Manager (AEM) Managed Services Support, v6.5 (Development)

Issue/Symptoms

  • Consistent warning messages appear in error logs about inability to delete Lucene files from MMapDirectory.

  • Warnings are logged for almost all indexes.

  • Example log entry:

    code language-none 
    org.apache.jackrabbit.oak.plugins.index.lucene.directory.CopyOnReadDirectory Couldn't compute safe timestamp to delete files from MMapDirectory@/mnt/crx/author/crx-quickstart/repository/index/fragments-[ timestamp] /data lockFactory=NativeFSLockFactory@/mnt/crx/author/crx-quickstart/repository/index/fragments-[ timestamp] /data

  • Typically occurs when reindexing is performed while AEM is running.

Resolution resolution

To ensure deletion of Lucene files from MMapDirectory:

  1. Stop the AEM Author instance.
  2. Back up the entire /crx-quickstart/repository/index directory.
  3. Clear the affected cache folders under /crx-quickstart/repository/index.
  4. Restart the AEM Author instance.

Additional Notes:

  • Deleting the cache directory is safe and doesn’t affect repository data. It will be rebuilt automatically after restart.
  • If warnings persist, check if reindexing was triggered recently or if index definitions or deployments were changed.

If the issue doesn’t resolve, please gather the following information and include it in an Adobe Support Ticket:

  1. Details on whether SegmentStore (TarMK) or MongoMK is used for author.
  2. Directory sizes for paths under /opt/aem/crx-quickstart/repository/index, such as damAssetLucene and ntBaseLucene.
  3. Relevant error log excerpts from when the warnings first appeared.
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