Sentinel stores data in file-based traditional storage and indexes data locally on the Sentinel server by default. When you enable event visualization, Sentinel stores and indexes data in Elasticsearch in addition to file-based traditional storage. The dashboards display only the events processed after you enabled event visualization. To view existing events present in file-based storage, you must migrate data from file-based storage to Elasticsearch. To migrate data to Elasticsearch, see Section 34.0, Migrating Data.