none
Exchange Server DR Site- Starting Mailbox Database and Client Access Services RRS feed

  • Question

  • Hello Folks,

    I need your suggestions on understanding and enabling the Mailbox and Client Access Services at DR Site.

    My Exchange environment:

    HQ Site

    2 Active Directory Servers

    2 Exchange 2016 Servers

    DR Site 

    1 Active Directory Server

    1 Exchange 2016 Server

    My 3 Exchange Servers are part of DAG, 2 Mailbox Databases, Active Copy at HQ Site and Passive at DR Site.

    I want to test my exchange mailbox database and client access services from DR server so i will disconnect the Link between HQ and DR site.

    I am assuming a scenario where my HQ site is totally down due to some disaster.

    In 3 member DAG servers where quorum model is used, Database copies will be activated on the site where two members are active.

    So my scenario is 2 HQ site members are down and i want to make a DR Site Database Copy as active.

    Appreciate if anyone can give suggestions and tips to activate the Database at DR site Exchange.

    Thanks,

    Arif

    Friday, June 21, 2019 10:39 AM

All replies

  • Hello Folks,

    I need your suggestions on understanding and enabling the Mailbox and Client Access Services at DR Site.

    My Exchange environment:

    HQ Site

    2 Active Directory Servers

    2 Exchange 2016 Servers

    DR Site 

    1 Active Directory Server

    1 Exchange 2016 Server

    My 3 Exchange Servers are part of DAG, 2 Mailbox Databases, Active Copy at HQ Site and Passive at DR Site.

    I want to test my exchange mailbox database and client access services from DR server so i will disconnect the Link between HQ and DR site.

    I am assuming a scenario where my HQ site is totally down due to some disaster.

    In 3 member DAG servers where quorum model is used, Database copies will be activated on the site where two members are active.

    So my scenario is 2 HQ site members are down and i want to make a DR Site Database Copy as active.

    Appreciate if anyone can give suggestions and tips to activate the Database at DR site Exchange.

    Thanks,

    Arif

    Follow this and document for your environment

    https://docs.microsoft.com/en-us/exchange/high-availability/manage-ha/datacenter-switchovers?view=exchserver-2019

    Friday, June 21, 2019 10:42 AM
    Moderator
  • Hi David,

    Thanks for the reply !

    I have documented below steps but need some advise on the same, Can you please reply to the highlighted words.

    • Validate and Confirm the prerequisites for the second datacenter
      • Check the Active Directory Service at DR Site
      • Check the Network Service at DR site
      • Check the Exchange Services at DR site
    • Terminating a partially failed datacenter ( Not Applicable as I am disconnecting the WAN Link only )
      • The Stop-DatabaseAvailabilityGroup cmdlet should be run against all servers in the primary datacenter. If the Mailbox server is unavailable but Active Directory is operating in the primary datacenter, the Stop-DatabaseAvailabilityGroupcommand with the ConfigurationOnly parameter must be run against all servers in this state in the primary datacenter, or the Mailbox server must be turned off. Failure to either turn off the Mailbox servers in the failed datacenter or to successfully perform the Stop-DatabaseAvailabilityGroup command against the servers will create the potential for split-brain syndrome to occur across the two datacenters. You may need to individually turn off computers through power management devices to satisfy this requirement.
      • The second datacenter must now be updated to represent which primary datacenter servers are stopped. This is done by running the same Stop-DatabaseAvailabilityGroup command with the ConfigurationOnly parameter using the same ActiveDirectorySite parameter and specifying the name of the Active Directory site in the failed primary datacenter. The purpose of this step is to inform the servers in the second datacenter about which mailbox servers are available to use when restoring service.

    Activating the Mailbox Servers

    • When the DAG is in DAC mode, the steps to complete activation of the mailbox servers in the second datacenter are as follows:
    • The Cluster service must be stopped on each DAG member in the second datacenter. You can use the Stop-Service cmdlet to stop the service (for example, Stop-Service ClusSvc), or use net stop clussvc from an elevated command prompt.
    • The Mailbox servers in the standby datacenter are then activated by using the Restore-DatabaseAvailabilityGroup cmdlet. The Active Directory site of the standby datacenter is passed to the Restore-DatabaseAvailabilityGroup cmdlet to identify which servers to use to restore service and to configure the DAG to use an alternate witness server. If the alternate witness server wasn't previously configured, you can configure it by using the AlternateWitnessServer and AlternateWitnessDirectory parameters of the Restore-DatabaseAvailabilityGroup cmdlet. If this command succeeds, the quorum criteria are shrunk to the servers in the standby datacenter. If the number of servers in that datacenter is an even number, the DAG will switch to using the alternate witness server as identified by the setting on the DAG object.

    ( I have single server only so Stopping cluster Service and Executing Restore-DatabaseAvailabilityGroup Command is enough for me to activate Database copies ?)

    • The databases can now be activated. Depending on the specific configuration used by the organization, this may not be automatic. If the servers in the standby datacenter have an activation blocked setting, the system won't do an automatic failover from the primary datacenter to the standby datacenter of any database. If no failover restrictions are present for any of the database copies in the standby datacenter, the system will activate copies in the second datacenter assuming they are healthy. If databases are configured with an activation blocked setting that requires explicit manual action, there are two choices for action:
    • Clear the setting that blocks activation. This will make the system return to its default behavior, which is to activate any available copy.
    • Leave the setting unchanged and use the Move-ActiveMailboxDatabase cmdlet to complete the database activation in the second datacenter. To complete this step using the Move-ActiveMailboxDatabase cmdlet when activation blocked is set, you must explicitly identify the target of the move.
    • The last step is to review all error and warning messages from the tasks. Any indicated warnings should be followed up and corrected. The task design model for these commands is to only fail if they can't achieve the fundamental goal of their design. For example, the Restore-DatabaseAvailabilityGroup cmdlet will fail if it can't shrink the quorum of the DAG to allow a server in the second datacenter to be restarted for servicing without causing a quorum outage. However, each task's output is also used to identify the issues that require administrator follow-up. You're strongly encouraged to save all task output and review it for follow-up actions.

    Activating Client Access services

    • Add the DNS records pointing to DR Exchange Server
    • Clients connect to service endpoints (for example Outlook on the web, Autodiscover, Exchange ActiveSync, Outlook Anywhere, POP3, IMAP4, and the RPC Client Access services array) to access Exchange services and data. Therefore, activating Client Access services involves changing the mapping of the DNS records for these service endpoints from IP addresses in the primary datacenter to the IP addresses in the second datacenter that are configured as the new service endpoints. Depending on your DNS configuration, the DNS records that need to be modified may or may not be in the same DNS zone
    • Clients will then automatically connect to the new service endpoints in one of two ways:
    • Clients will continue to try to connect, and should automatically connect after the TTL has expired for the original DNS entry, and after the entry is expired from the client's DNS cache. Users can also run the ipconfig /flushdns command from a command prompt to manually clear their DNS cache.
    • Clients starting or restarting will perform a DNS lookup on startup and will get the new IP address for the service endpoint, which will be an Exchange server running Client Access services, or a Client Access services array, in the second datacenter.
    • Assuming that all appropriate configuration changes have been completed to define and configure the services in the second datacenter to function as they were in the primary datacenter, and assuming that the established DNS configuration is correct, no further changes should be needed to activate Client Access services.

    Activating Transport services

    Clients and other servers that submit messages typically identify those servers using DNS. Activating transport services in the second datacenter involves changing DNS records to point to the IP addresses of the Mailbox servers in the second datacenter. Clients and sending servers will then automatically connect to the servers in the second datacenter in one of two ways:

    • Clients will continue to try to connect, and should automatically connect after the TTL has expired for the original DNS entry, and after the entry is expired from the client's DNS cache. Users can also run the ipconfig /flushdns command from a command prompt to manually clear their DNS cache.
    • Clients starting or restarting will perform a DNS lookup on startup and will get the new IP address for the SMTP endpoint, which will be a Mailbox server in the second datacenter.

    Assuming that all appropriate configuration changes have been completed to define and configure the services in the second datacenter to function as they were in the primary datacenter, and assuming that the established DNS configuration is correct, no further changes should be needed to activate transport services.

    Once the Mailbox and Client Access services are tested on the DR Exchange, I want to put it back as the DAG Member and to run the passive copies of Mailbox Databases

    Steps to be performed:

    • Dismount the Mailbox Databases
    • Start the Cluster Service
    • Point the DNS to HQ Site servers
    • Connect back the WAN link and wait for Database Replication

    Above steps should be fine or need to do additional tasks to make it work like a pervious DAG Member


    Friday, June 21, 2019 6:57 PM
  • Hi,

    Since you have 3 DAG members, 2 nodes must always be online for your Exchange Cluster to remain operational. You need an alternate Witness Server in DR site to achieve quorum during a Datacenter Switchover. Here is a blog may help you know more about Exchange site resilient: Exchange 2010 Site Resilient DAGs and Majority Node Set Clustering – Part 2

    Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link.

    The process of restoring service to a previously failed datacenter is referred to as a switchback. The steps used to perform a datacenter switchback are similar to the steps used to perform a datacenter switchover. After switchback to the primary datacenter is completed successfully, you can reestablish site resilience for the primary datacenter by verifying the health and status of each mailbox database copy in the second datacenter.

    Regards,

    Lydia Zhou


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Monday, June 24, 2019 10:36 AM
    Moderator
  • Hi,

    Just checking in to see if above information was helpful.

    If you have any questions or need further help on this issue, please feel free to post back.

    Regards,

    Lydia Zhou


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Friday, June 28, 2019 1:50 AM
    Moderator
  • Hi Zhou,

    I followed the below link for datacenter switchover on activating the mailbox databases at DR Exchange we got the below error.

    https://docs.microsoft.com/en-us/exchange/high-availability/manage-ha/datacenter-switchovers?view=exchserver-2019

     C:\Windows\system32>

    PS>Move-ActiveMailboxDatabase -Identity MDB01
    Active Manager isn't reachable on server hqex-01.contoso.local. The Microsoft Exchange Replication service might 
    not be running. Error Error 0x6ba (The RPC server is unavailable) from cli_GetPrimaryActiveManager.
        + CategoryInfo          : InvalidOperation: (MDB01:ADObjectId) [Move-ActiveMailboxDatabase], 
    InvalidOperationException
        + FullyQualifiedErrorId : [Server=HQEX-DR,RequestId=146f8929-4afe-4463-8269-b4ce7e2ae4d1,TimeStamp=6/25/2019 
    7:27:42 AM] [FailureCategory=Cmdlet-InvalidOperationException] 
    342CB4B8,Microsoft.Exchange.Management.SystemConfigurationTasks.MoveActiveMailboxDatabase
        + PSComputerName        : hqex-dr.contoso.local
    Active Manager isn't reachable on server hqex-01.contoso.local. The Microsoft Exchange Replication service might
    not be running. Error Error 0x6ba (The RPC server is unavailable) from cli_GetPrimaryActiveManager.
        + CategoryInfo          : InvalidOperation: (MDB01:ADObjectId) [Move-ActiveMailboxDatabase], InvalidOperationExcep
       tion
        + FullyQualifiedErrorId : [Server=HQEX-DR,RequestId=146f8929-4afe-4463-8269-b4ce7e2ae4d1,TimeStamp=6/25/2019 7:27:
       42 AM] [FailureCategory=Cmdlet-InvalidOperationException] 342CB4B8,Microsoft.Exchange.Management.SystemConfigurati
      onTasks.MoveActiveMailboxDatabase
        + PSComputerName        : hqex-dr.contoso.local


    Sunday, June 30, 2019 5:20 AM
  • Hi,

    As the error information mentioned, you should check Microsoft Exchange Replication service on the server hqex-01.contoso.local. Try to restart this service manually, then run Move-ActiveMailboxDatabase again. If Microsoft Exchange Replication service cannot be started manually, you can check application logs for further analysis.

    Additionally, you can use the ActivateOnServer parameter in the command to specify the name of the Mailbox server on which the mailbox database copy should be activated.

    Regards,

    Lydia Zhou


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Tuesday, July 2, 2019 5:58 AM
    Moderator
  • Hi,

    Just checking in to see if above information was helpful.

    Please let us know if you would like further assistance. If you have solved your problem, could you share with us? Maybe it will help more people with similar problems. 

    Regards,

    Lydia Zhou


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Tuesday, July 9, 2019 1:40 AM
    Moderator
  • No Zhou,

    it didn't help, I am still searching.

    thanks

    Tuesday, July 9, 2019 1:13 PM
  • Hi,

    Is DAC mode enabled for your DAG?

    As is mentioned above, since you have 3 nodes, 2 nodes must be up to get the quorum. Please check and make sure the alternate witness server is online.

    Regards,

    Lydia Zhou


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Thursday, July 11, 2019 6:48 AM
    Moderator