In continuation with previous post Part 1 , we will now perform the datacenter failover and failback. In the first scenario, we will bring the production site down and activate the DR site. Later, we will bring up the production site and failback the resources to the production Exchange server.

Failover

Step1: Shutdown Exchange in primary site

Step2: Outlook Client & OWA status

Step3: Run Stop-DatabaseAvailabilityGroup -Identity DAG-Exch2019 ActiveDirectorySite Prod

Step4: Stop cluster service on DR server

Step5: Restore-DatabaseAvailabilityGroup -Identity DAG-Exch2019 -ActiveDirectorySite DR -AlternateWitnessServer adc.CloudExchangers.com

Get-DatabaseAvailabilityGroup -Status |fl Name,Servers,OperationalServers,*mailboxservers,*ipv4*,*mode,*manager,*witness*

Step6: DNS change

Client machine checks

Outlook connected without restarting

New outlook profile configured – autodiscover works fine

Email Header confirmation:

Received: from EXCH2.CloudExchangers.com (10.2.0.4) by

EXCH2.CloudExchangers.com (10.2.0.4) with Microsoft SMTP Server

(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2

via Mailbox Transport; Thu, 31 Dec 2020 12:37:53 +0400

Received: from EXCH2.CloudExchangers.com (10.2.0.4) by

EXCH2.CloudExchangers.com (10.2.0.4) with Microsoft SMTP Server

(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2;

Thu, 31 Dec 2020 12:37:45 +0400

Received: from EXCH2.CloudExchangers.com ([fe80::a8b6:f3d6:5c65:55d5]) by

EXCH2.CloudExchangers.com ([fe80::a8b6:f3d6:5c65:55d5%6]) with mapi id

15.02.0721.002; Thu, 31 Dec 2020 12:37:45 +0400

Content-Type: application/ms-tnef; name=”winmail.dat”

Content-Transfer-Encoding: binary

From: User 1 <[email protected]>

To: Manager 1 <[email protected]>

Subject: Test Email from DR

Thread-Topic: Test Email from DR

Thread-Index: AdbfUDPiMUuspwhEQlCY5KAfBI6tHg==

Date: Thu, 31 Dec 2020 12:37:44 +0400

Message-ID: <[email protected]>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach:

X-MS-Exchange-Organization-SCL: -1

X-MS-TNEF-Correlator: <[email protected]>

MIME-Version: 1.0

X-MS-Exchange-Organization-MessageDirectionality: Originating

X-MS-Exchange-Organization-AuthSource: EXCH2.CloudExchangers.com

X-MS-Exchange-Organization-AuthAs: Internal

X-MS-Exchange-Organization-AuthMechanism: 04

X-Originating-IP: [192.168.0.4]

X-MS-Exchange-Organization-Network-Message-Id: 6834af99-a6c5-4327-d131-08d8ad6758bd

Return-Path: [email protected]

X-MS-Exchange-Organization-AVStamp-Enterprise: 1.0

X-MS-Exchange-Transport-EndToEndLatency: 00:00:08.8593422

X-MS-Exchange-Processed-By-BccFoldering: 15.02.0721.002

We have successfully activated the DR site using Restore-DAG and tested the client connectivity and mail flow.

Now, let’s assume that the issue with primary site Exchange server has been resolved and powered on. It’s time to bring back the services to the production site.

Failback

Step1: Power on Prod servers

Step2: Stop Cluster service on EXCH1

Step3: Start-DatabaseavailabiltyGroup –Identity DAG-Exch2019 –ActiveDirectorySite Prod

Step4: Run Set-DatabaseAvailabilityGroup

Check the Database status

Step5: Move Cluster group

Step6: Move Database

DAG and Database status

Step7: DNS change

Client Connectivity checks

Email header confirmation:

Received: from EXCH1.CloudExchangers.com (10.1.0.4) by

EXCH1.CloudExchangers.com (10.1.0.4) with Microsoft SMTP Server

(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2

via Mailbox Transport; Thu, 31 Dec 2020 13:03:06 +0400

Received: from EXCH1.CloudExchangers.com (10.1.0.4) by

EXCH1.CloudExchangers.com (10.1.0.4) with Microsoft SMTP Server

(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2;

Thu, 31 Dec 2020 13:02:59 +0400

Received: from EXCH1.CloudExchangers.com ([fe80::3535:c800:f655:5750]) by

EXCH1.CloudExchangers.com ([fe80::3535:c800:f655:5750%7]) with mapi id

15.02.0721.002; Thu, 31 Dec 2020 13:02:58 +0400

Content-Type: application/ms-tnef; name=”winmail.dat”

Content-Transfer-Encoding: binary

From: User 1 <[email protected]>

To: Manager 1 <[email protected]>

Subject: Test Failback

Thread-Topic: Test Failback

Thread-Index: AQHW31O2iKlck36K4UuJthELfioJhA==

Date: Thu, 31 Dec 2020 13:02:56 +0400

Message-ID: <[email protected]>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach:

X-MS-Exchange-Organization-SCL: -1

X-MS-TNEF-Correlator: <[email protected]>

MIME-Version: 1.0

X-MS-Exchange-Organization-MessageDirectionality: Originating

X-MS-Exchange-Organization-AuthSource: EXCH1.CloudExchangers.com

X-MS-Exchange-Organization-AuthAs: Internal

X-MS-Exchange-Organization-AuthMechanism: 04

X-Originating-IP: [192.168.0.4]

X-MS-Exchange-Organization-Network-Message-Id: 01d90fa1-b1e2-4f53-b105-08d8ad6ade78

Return-Path: [email protected]

X-MS-Exchange-Organization-AVStamp-Enterprise: 1.0

X-MS-Exchange-Transport-EndToEndLatency: 00:00:10.0039826

X-MS-Exchange-Processed-By-BccFoldering: 15.02.0721.002

Great!! We have successfully performed the datacenter failover and failback for Exchange 2019. We will continue with another scenario for the DR in my next post.

Happy learning!! 🙂

By Ashok M

A technology enthusiast with 9+ years of experience in Planning, Designing, Implementation, Migration and Operations of various Microsoft Infrastructure & Cloud Services. Extensive knowledge of Cloud Computing, Microsoft Messaging & Collaboration, Digital Transformation, IT Services & Emerging technologies. • One of the Authors of the book – “Reimagine Remote Working with Microsoft Teams : A practical guide to increasing your productivity and enhancing collaboration in the remote world” - https://www.amazon.com/Reimagine-Remote-Working-Microsoft-Teams/dp/1801814163 • Blogger at CloudExchangers - https://cloudexchangers.com/ • Microsoft Community Contributor in Microsoft Q&A - https://docs.microsoft.com/en-us/users/ashokm-8240 • Microsoft Certified Professional in MS Azure, Microsoft365, MS Teams and Skype for Business