Indexing Version 2: Index Cleanup
In Indexing Version 1, indexes were subject to being deleted from the index cache after a period of time (or sooner, if the index cache directory was nearly full). This deleting process is called cleanup. In Version 2, the actual indexes are never deleted from the Index Directory, but the log files are deleted after the index has been backed up.
Log files are backed up to the library to which the data is backed up. When the index is backed up (see Version 2 Index Backup), the log files are deleted from the MediaAgent. Log files are restored if needed to rebuild an index from its last backup.
The index database is backed up when the criteria are met for the index (see Index Backup Criteria), but unlike Indexing Version 1, it is never deleted in normal operations. It is left in the Index Directory for further update, and for access to support normal operations (such as browse and find), as required.
Note: Although indexes are not deleted during normal operations, if you delete a backup set from a subclient, the index for that backup set gets deleted from the Indexing MediaAgent.