Recover Exchange servers

You can recover a lost Exchange server by using the Mode:RecoverServer switch in unattended mode (from the command line) of Exchange Setup. Since most Exchange server settings are stored in Active Directory, the Setup.exe /Mode:RecoverServer command uses that information during the installtion of Exchange on a new server with the same name.

Recovering a lost Exchange server is often accomplished by using new hardware. However, you can also use an existing server that doesn't already have Exchange installed on it.

This topic shows you how to recover a lost Exchange server that isn't a member of a database availability group (DAG). For detailed steps about how to recover a server that was a member of a DAG, see Recover a database availability group member server.

Note: If Exchange is installed in a location other than the default location of %ProgramFiles%\Microsoft\Exchange Server\V15, you must include the /TargetDir:<Path> switch in the Setup.exe /Mode:RecoverServer command to specify the location of the Exchange program (binary) files. If you don't use the /TargetDir switch, the Exchange files will be installed in the default location when you recover the Exchange server.

Do the following steps to find the install location of Exchange on the lost Exchange server:

  1. Open ADSIEDIT.MSC or LDP.EXE.

  2. Go to CN=ExServerName,CN=Servers,CN=First Administrative Group,CN=Administrative Groups,CN=ExOrg Name,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=DomainName,CN=Com

  3. Right-click the Exchange server object, and then click Properties.

  4. Find the msExchInstallPath attribute. This attribute stores the current installation path.

Looking for other management tasks related to backing up and restoring data? Check out Backup, Restore, and Disaster Recovery.

What do you need to know before you begin?

  • Estimated time to complete: 20 minutes

  • You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Exchange infrastructure permissions" section in the Exchange infrastructure and PowerShell permissions topic.

  • You can recover a server using the latest avaialble Cumulative Update (CU). Only the last two CUs are available for download. For more information, see Updates for Exchange Server.

  • The target server must use the same version of Windows Server as the lost server. For example, you can't recover a lost Exchange 2016 server that was running Windows Server 2012 on a new server that's running Windows 2012 R2, or vice-versa.

  • The same disk drive letters that were used for mounted databases on the lost server must also exist on the target server.

  • The target server should have the same general performance characteristics and hardware configuration as the lost server.

  • For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard shortcuts in the Exchange admin center.

Tip

Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server, Exchange Online, or Exchange Online Protection..

Recover a Lost Exchange Server

  1. Reset the computer account for the lost server. For detailed steps, see Reset a Computer Account.

  2. Install the proper operating system and name the new server with the same name as the lost server. Recovery won't succeed if the target Windows server doesn't have the same name as the lost Exchange server.

  3. Join the server to the same domain as the lost server.

  4. Install the necessary prerequisites and operating system components on the target server. For details, see Exchange Server system requirements.

  5. On the target server, open File Explorer, right-click on the Exchange ISO image file that you downloaded, and then select Mount. Note the virtual DVD drive letter that's assigned.

  6. Opwn a Windows Command Prompt window. For example:

    • Press the Windows key + 'R' to open the Run dialog, type cmd.exe, and then press OK.

    • Press Start. In the Search box, type Command Prompt, then in the list of results, select Command Prompt.

  7. In the Command Prompt window, use the following syntax:

    <Virtual DVD drive letter>:\Setup.exe /IAcceptExchangeServerLicenseTerms /Mode:RecoverServer [/TargetDir:<Path>] [/DomainController:<ServerNameOrFQDN>] [/DoNotStartTransport] [/EnableErrorReporting]
    

    This example uses the Exchange installation files on drive E: to install Exchange in the default location (%ProgramFiles%\Microsoft\Exchange Server\V15) and recover the Exchange server.

    E:\Setup.exe /IAcceptExchangeServerLicenseTerms /Mode:RecoverServer
    

    This is the same example, but a custom location for the Exchange program files is required to match the location on the lost server.

    E:\Setup.exe /IAcceptExchangeServerLicenseTerms /Mode:RecoverServer /TargetDir:"D:\Program Files\Exchange"
    

For more information about the optional switches, see Use unattended mode in Exchange Setup.

  1. After Setup has completed, but before you put the recovered server into production, reconfigure any custom settings that were previously present on the server, and then restart the server.

How do you know this worked?

The successful completion of Setup will be the primary indicator that the recovery was successful. To further verify that you've successfully recovered a lost server, open the Windows Services tool (services.msc) and verify that the Microsoft Exchange services have been installed and are running.