Regardless of whether you have a DAG or a single mailbox database in Exchange infrastructure, sometimes database index can become corrupted and stuck in Failed / FailedAndSuspended state. If you have DAG that could be a problem, because you cannot move database to “failed” node.
Rebuilding content index can be done manually with following procedure. This process involves removing the existing content index files, which will trigger Exchange Search to re-index that database. The re-indexing process can cause a high load on the Exchange server, so you should carefully consider the timing of any content index rebuilds. The content index files are located in the same path as the database EDB file, in a sub-folder named with a GUID. Before the corrupt index files can be removed, the Exchange Search services must be stopped.
- Stop service MSExchangeFastSearch
- Stop service HostControllerService
- Delete the GUID.Single named folder
- Start service MSExchangeFastSearch
- Start service HostControllerService
Now, re-indexing will be started. Depend on database size, that action can take a lot of time. The content index will have a state of “Crawling” while this is occurring. With PS command Get–MailboxDatabaseCopyStatus –Server “ServerName” you can check content index state in any moment.