# Data Optimizer recovery mode In recovery mode, the Pentaho Data Optimizer volume operates with its metadata store in non-authoritative mode while recovering file system metadata. The term “non-authoritative” means that the contents of the local metadata store might be incomplete. As a result, certain metadata inquiries can only be serviced by making external API calls to the S3 storage device. The metadata retrieved from the S3 storage device is cached to the local metadata store, reducing the need for future external API calls. Data Optimizer volumes are fully functional while in recovery mode, though performance might be affected. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.pentaho.com/pdc-10.2-data-optimizer/pdso-install-landing-page/pdso-install-in-hadoop-cluster/pdso-maintain-landing-page/pdso-maintain-data-optimizer-metadata-cp/pdso-recovery-mode-explained.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.