Steps To Solve Content Index Failed Error

Note: This article applies to Exchange Server that is members of a Database Availability Group. These steps are common for versions higher than Exchange 2010.

On an Exchange Server, you may encounter failed content indexes that are preventing end users from being able to run searches in OWA and Outlook.

Failed content Index also stops you from activating the passive database copies during database switchover. There is a workaround to failover database with failed content index.  Microsoft Reference

To solve the problem, perform the following steps to repair the content index.

• Log into EMS and run below command to verify the content error.
  Get-MailboxDatabase Database Name | Get-MailboxDatabaseCopyStatus | Select Name,*index*

 Get-mailboxdatabase Database1 | get-mailboxdatabasecopystatus | select name, *index*

• Now run to below command to repair catalog of an affected database.
  Update-MailboxDatabaseCopy Database Name** –sourceserver Server Name* –catalogonly

Update-MailboxDatabasecopy Database1\Server1 –sourceserver Server2 –catalogonly

            _{Note : * Server name on which content index is in a healthy state.
                        ** Database name in format : Database1\Server1}

Updating of the catalog will take sometimes depend upon catalog size.

• Follow steps 1-3 to for all unhealthy copies.
• After that verify it once again by below command if content Index State is changed to healthy.

 Get-MailboxDatabase Database Name | Get-MailboxDatabaseCopyStatus | Select Name,*index*

 Get-mailboxdatabase Database1 | get-mailboxdatabasecopystatus | select name, *index*

If the server is not part of DAG, we will have a single copy of the database and the content index is corrupted? How do we get it back to a healthy state? All we need is to delete the catalog folder & it’s subfolders after stopping the search service.

In Exchange 2013/2016:

• Stop the Microsoft Exchange Search and Microsoft Exchange Search Host Controller service.
• From Shell;

             Stop-Service MSExchangeFastSearch
             Stop-Service HostControllerService 

• Browse to where the database files are located on the disk. Along with the database file, you will see a folder with a long string as the name. It will have three sub-folders as well. Delete the main folder along with the sub-folders. This is the folder where the index is stored.

• Restart the Microsoft Exchange Search and Microsoft Exchange Search Host Controller service. 
• From Shell;

           Start-Service MSExchangeFastSearch
           Start-Service HostControllerService 

•  Give it a minute and a new folder will be created and a new index will be built.

In Exchange 2010:

• Stop the Microsoft Exchange Search Indexer service. 
• From Shell;

            Stop-Service MSExchangeSearch

•    Browse to where the database files are located on the disk. Along with the database file, you will see a folder with “CatalogData-random string” as its name. Delete this folder, which stores the corrupt index.

• Restart the Microsoft Exchange Search Indexer service. 
• From Shell;

           Start-Service MSExchangeSearch

• Give it a minute and a new folder will be created and a new index will be built.

Hope these instructions have helped you out!