Introduction

Before installing Exchange Server 2019, it is crucial to prepare your Active Directory (AD) environment. This preparation involves extending the AD schema, preparing the AD forest and domains, and ensuring that your AD infrastructure is ready to support Exchange Server 2019. This guide will walk you through each step, ensuring a smooth and successful installation.

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1. Understanding Active Directory Preparation

1.1. Why AD Preparation is Necessary

• Active Directory is the backbone of an Exchange Server deployment. It stores and replicates the configuration and recipient data for the Exchange organization across all domain controllers in your AD forest.
• Preparing AD ensures that Exchange Server 2019 can integrate seamlessly with your existing AD infrastructure, allowing for efficient management and operation of your messaging environment.

1.2. Overview of AD Preparation Steps

• Extend the AD Schema: Update the AD schema to include Exchange Server 2019-specific attributes and classes.
• Prepare the AD Forest: Configure the entire AD forest to support Exchange Server 2019.
• Prepare AD Domains: Prepare each domain in the forest where Exchange will be installed or where mail-enabled objects will be managed.

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2. Pre-Preparation Checklist

Before you begin, ensure the following prerequisites are met:

2.1. Permissions

• You must be a member of the Schema Admins and Enterprise Admins groups to extend the schema and prepare the forest.
• To prepare domains, you need to be a member of the Domain Admins group in each domain that you are preparing.

2.2. Active Directory Health

• Ensure that all domain controllers are healthy and that AD replication is functioning correctly across all sites. Use the dcdiag and repadmin tools to verify AD health and replication status.

2.3. Backup

• It’s advisable to take a full backup of your AD environment before making any changes. This provides a fallback option in case any issues arise during the preparation process.

2.4. Active Directory Functional Levels

• The forest functional level must be Windows Server 2012 R2 or higher to support Exchange Server 2019.

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3. Extending the Active Directory Schema

3.1. Download Exchange Server 2019 Installation Media

• Obtain the Exchange Server 2019 installation files from Microsoft and mount the ISO or extract the files.

3.2. Run Schema Extension Command

• Open a Command Prompt with administrative privileges and navigate to the directory where the Exchange installation files are located. Run the following command:
  cmd

  Setup.exe /PrepareSchema /IAcceptExchangeServerLicenseTerms

• This command will extend the AD schema by adding Exchange Server 2019-specific classes and attributes.

3.3. Verifying Schema Extension

• After the schema extension completes, verify that it was successful by checking the schema version in AD. You can do this using the ADSI Edit tool or by running the following PowerShell command:
  powershell

  Get-ADObject (Get-ADRootDSE).schemaNamingContext -Property objectVersion

• The objectVersion should be 170, which corresponds to Exchange Server 2019.

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4. Preparing the Active Directory Forest

4.1. Run Forest Preparation Command

• After extending the schema, prepare the AD forest by running the following command:
  cmd

  Setup.exe /PrepareAD /OrganizationName:"YourOrganizationName" /IAcceptExchangeServerLicenseTerms

• Replace "YourOrganizationName" with the name of your Exchange organization.

4.2. What the Command Does

• This command creates global Exchange objects in the AD configuration partition, such as the Exchange Organization container. It also grants necessary permissions to the Exchange servers.

4.3. Verifying Forest Preparation

• To confirm that the forest preparation was successful, use the ADSI Edit tool to check that the Exchange organization objects were created in the AD configuration partition.

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5. Preparing Active Directory Domains

5.1. Run Domain Preparation Command

• Prepare each domain in the forest where Exchange will be installed or where mail-enabled objects will be managed by running:
  cmd

  Setup.exe /PrepareDomain /IAcceptExchangeServerLicenseTerms

• If your environment has multiple domains, you can prepare all domains in the forest by running:
  cmd

  Setup.exe /PrepareAllDomains /IAcceptExchangeServerLicenseTerms


5.2. What the Command Does

• This step creates domain-specific objects, such as the Microsoft Exchange System Objects container, and configures the necessary permissions for Exchange.

5.3. Verifying Domain Preparation

• Use the Active Directory Users and Computers (ADUC) console to check for the creation of the Microsoft Exchange System Objects container in each prepared domain.

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6. Best Practices for AD Preparation

6.1. Staged AD Preparation

• Consider performing the AD preparation steps in a staged manner, starting with a test environment or a less critical domain to ensure everything functions as expected before preparing the entire forest.

6.2. Monitoring and Logging

• Enable logging when running the AD preparation commands by using the /log parameter. This creates a detailed log file that can be reviewed for any errors or issues that occur during the preparation.

6.3. Post-Preparation Validation

• After preparing AD, verify that all domain controllers have received the updates by checking replication status. Ensure that all changes have been successfully replicated across the forest.

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7. Troubleshooting AD Preparation

7.1. Common Issues

• Replication Delays: If AD replication is slow, you might encounter errors when trying to prepare domains immediately after preparing the forest. Wait for replication to complete, then try again.
• Permission Errors: Ensure that the account you are using has the necessary permissions to extend the schema and prepare the forest/domains.

7.2. Using Setup Logs

• Review the setup logs located in the %ExchangeSetupLogs% directory for detailed information about any issues encountered during the AD preparation process.

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Conclusion

Properly preparing Active Directory is a critical first step in deploying Exchange Server 2019. By following the steps outlined in this guide, you can ensure that your AD environment is ready to support Exchange Server 2019, setting the stage for a successful installation and operation.

For further assistance or advanced configurations, consult additional Knowledge Base articles or reach out to our support team.