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Installing Exchange Server 2007 or 2010 on a domain controller is not recommended by Microsoft, however what if it is installed?

Consider a scenario wherein we have two domain controllers in a single site with exchange server 2010 installed on one domain controller. Now that domain controller is crashed.

The only data which is available with me now is the AD system state and Exchange Database. My main goal is to get the Exchange Server back, how do I get my exchange sever back?

Since I had two domain controllers in the site I have all my user objects in the primary DC.

In this step by step article I will show you how to get rid of the crashed DC and at the same time how to bring the Exchange Server back with a supported scenario.

Before you begin

The account with which we are performing the task should be a member of Enterprise Admin, Domain Admin & Schema Admin.

A valid fully tested Exchange Database for restore (Online or Offline).

Exchange Server 2010 configuration information such as

Number of Drives

Exchange Install Path

Exchange Database Path

Exchange Transaction Log Path

Roles & etc.

Important: Ensure that the above exchange information is in place before you procure a new hardware. Any mismatch can cause the whole process to fail. And you may end up troubleshooting that issue for many hours.

Scenario: 1

Checklist before we perform the task.

Figure 1.1: Netdom example showing the list of domain controllers and the hostname.

In the above example we are having two domain controllers with Exchange installed on “DCE14”

Figure 1.2: Exchange Server Name with all Roles

DCE14 has all three roles installed.

Figure 1.3: Number of Mailboxes this Exchange Server hosts

Since this is a test environment I have created few mailboxes for testing purposes.

Figure 1.4: Test Email was sent before the crash occurs

Figure 1.5: Exchange Server “DCE14” crashed due to hardware failure

In figure 1.4 the Server crashed due to hardware failure. We will be restoring the same Exchange Server on a member server.

Scenario: 2

In scenario 1 what we have learnt is to keep valuable information and the database to ensure that we will be able to perform disaster recovery using the

“setup.com /m:RecoverServer” option.

How do we achieve this is what we are going to do in scenario 2.

Since the Domain controller (DCE14) is crashed. We will be performing Metadata Cleanup of the crashed DC.

In Windows Server 2008 R2 it is pretty straight forward. We have three options to perform Metadata Cleanup.

Option Number 1: GUI

Option Number 2: Command Line using NTDSUtil (Built-in)

Option Number 3: Script

In this scenario I will be using the GUI option to perform the Metadata Cleanup.

Log in to the Root Domain controller and open Active Directory Users & Computers and select the crashed server as shown below and go to properties. Select Member of Tab and make a note of the computer membership.

Figure 2.1: Before you delete the object. Please make a note of the above Information.

Once the above information is in place. Then select the below option to delete the DC.

Figure 2.2: Right click the Domain Controller and select Delete

Figure 2.3: Warning “Are you sure you want to delete the Computer Named DCE14”

Just click on Yes.

Figure 2.4: Check the Box since the domain controller is offline and can no longer be demoted using “DCPROMO” and then click on Delete.

Figure 2.5: This is a Global Catalog. Click on Yes.

Figure 2.6: In the above screen just click on Yes post understanding the Warning.

The domain controller is completely removed.

Open Sites and Services and Select the Domain Controller as shown below.

Figure 2.7: Select the above option to delete the object from Sites & Services.

Once the above steps are done. Ensure that DNS entries are deleted from DNS console.

Figure 2.8: Delete all DNS entries including the SOA records.

Domain Controller information is deleted and it is gone forever. Now it is possible for us to bring back a member server by the same name.

If you have opted for a new hardware then install Windows Server 2008 R2 and then rename the computer by the same name as “DCE14“. Once the computer is renamed then make the server as a member of domain controller “ems.com”

Figure 2.9: DCE14 being added as a member server.

Figure 2.10: Server is added successfully.

Once it is done. Open Active Directory Users & Computers and select the computer “DCE14” from computers “OU” and go to properties.

Make the computer as a member of as shown in Figure 2.1.

Once it is done. Open ADSIEDIT and go to the following location.

CN=DCE14, CN=Servers, CN=Exchange Administrative Group, CN=Administrative Group, CN=EMS, CN=Microsoft Exchange, CN=Services, CN=Configuration, DC=EMS, DC=Com

Right click DCE14 and then go to properties. Select Security and remove the Unresolved SID if any. And then click on Add…. To add the new member server in this location as shown below.

Figure 2.11: Member server DCE14 being added and given the default permission.

Now it’s time to begin the installation of Exchange Server. Install all prerequisites for installing Exchange Server 2010 SP1.

Open command prompt and type as follows.

Figure 2.12: Installation of Exchange Server 2010 SP1 completed successfully.

Open EMC and then Select the Mailbox Database and go to properties as shown below.

Figure 2.13: Select the checkbox “This database can be overwritten by a restore”

Since we have performed a Disaster Recovery the database would be in dismounted state. Do not mount the database without restoring the database.

Perform a restore based on the backup available. In our scenario I have used Windows Server Backup Feature which is available as a built-in feature.

Once the restore is done then Mount the database.

Figure 2.14: Select Mount database.

Figure 2.15: Mailbox Database Mounted successfully.

Login to the mailbox and check if you can send and receive email.

Figure 2.16: Welcome Back

I hope that the above article is helpful and saves your valuable time. The scenario may differ from company to company, however if the information what is required is in place then it’s very easy to bring the exchange server in just 2 hours.

Happy Learning

Sunder

Team@ MSExchangeGuru.com

Posted February 27th, 2011 under Best Practices, Exchange 2010. RSS 2.0 feed. Leave a response, or trackback.