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Protecting virtual machines during live migration

Updated: November 1, 2013

Applies To: System Center 2012 R2 Data Protection Manager, System Center 2012 SP1 - Data Protection Manager

This section provides information about how you can deploy System Center 2012 - Data Protection Manager (DPM) to effectively protect virtual machines that are running Microsoft Hyper-V during live migration.

Live migration scenarios

DPM can back up the following live migration scenarios:

  • Live migration within a cluster—When a virtual machine is migrated within a cluster, DPM detects the migration and backs up the virtual machine from the new cluster node without user intervention. Because there are no changes to storage, DPM continues with express full backups. If two DPM servers protect a cluster, a virtual machine that is protected by the first DPM server continues to be protected by the same DPM server after the migration, no matter where it is located.

  • Live migration outside a single cluster—When a virtual machine is migrated outside a single cluster, you can perform live migration between two stand-alone servers, between a stand-alone server and a cluster node, or between two nodes from different clusters. In this scenario, DPM detects the migration and can perform backups without user intervention. The backups require the following configuration:

    • The virtual machines are managed in a cloud that is configured on a VMM management server that is running System Center 2012 SP1.

    • The DPM servers are connected to the VMM management server on which the private cloud is located.

    • All servers that are running Hyper-V are connected to all DPM servers.

With these prerequisites in place, DPM communicates with VMM to locate where the virtual machine currently runs, and can then create a backup from the new server that is running Hyper-V. DPM can communicate with the new server that is running Hyper-V because all servers that are running Hyper-V are connected to all DPM servers. If this connection cannot be established, the backup fails with a message that the DPM protection agent is unreachable.

Storage migration

If a live migration transfers storage, DPM performs a full consistency check of the virtual machine, and then continues with express full backups. If there is no storage migration involved, for example if the source and target locations both use the same server message block (SMB) 3.0 file server, then DPM continues to perform express full backups without the consistency check.

Configure DPM protection for live migration

Before you start, note or do the following:

  • DPM protection for live migration is only available on servers that are running Windows Server 2012.

  • Live migration protection does not support backup of data to tape, neither disk-to-tape nor disk-to-tape-to-tape.

  • DPM performs a one-time consistency check for all live migrations that include storage migration.

  • When live migration of storage occurs, Hyper-V reorganizes the virtual hard disk (VHD) or VHDX and therefore there is a one-time spike in the size of DPM backup data.

  • Turn on auto-mount on the virtual machine host to enable virtual protection.

  • Disable the feature TCP Chimney Offload.

  • These steps assume that you have installed the DPM server and have configured DPM storage. For more information, see Installing DPM, and Configuring disk storage.

Then complete the following steps:

  1. Verify that the DPM servers, VMM management servers, and servers that are running Hyper-V are located in the same domain.

  2. Deploy the DPM protection agent on all computers that are to host virtual machines. For instructions, see Installing and Configuring Protection Agents.

  3. Install the VMM console as the VMM client component on all DPM servers to enable the DPM server to communicate with and track the VMM management server. Note the following:

    1. The DPMMachineName$ account should be a read-only administrator account on the VMM management server.

    2. Ensure that the VMM console is of the same version as the VMM management server that is used in the deployment.

  4. Set the Global Property value for the KnownVMMServerName by using Windows PowerShell, as follows:

    Set-DPMGlobalProperty -dpmservername <dpmservername> -knownvmmservers <vmmservername>.

    This command connects all the servers that are running Hyper-V to all the DPM servers. The cmdlet accepts multiple DPM server names. For usage instructions, see Set-DPMGlobalProperty.

  5. Create protection groups in DPM by using the New Protection Group Wizard. Note that automatic consistency check should be enabled at the protection group level for protection under virtual machine mobility scenarios.

    ImportantImportant
    Enable the DPM VMM communication first. All virtual machines on servers that are running Hyper-V should be discovered before you configure the protection groups. Otherwise, live migration does not work as expected, and the user has to stop to protect data with Retain Data, and then reconfigure protection for the same computer.

After settings are configured, when a virtual machine migrates from one cluster to another, all backups continue as expected. You can then use the Recovery Wizard as required. Note that after you complete the steps, live migration is enabled after the DPM Summary Manager job runs. By default, this job starts at midnight and runs every morning. For information about how to run a live migration immediately, see Manually run a live migration.

Verify that live migration is enabled as expected

Verify settings as follows:

  1. Ensure that the service DPM-VMM Helper Service is running. If it is not running, start it. If it already runs, continue to the next step.

  2. Open Microsoft SQL Server Management Studio and connect to the instance that hosts the DPM database (DPMDB).

  3. On DPMDB, run the following query: SELECT TOP 1000 [PropertyName] ,[PropertyValue] FROM[DPMDB].[dbo].[tbl_DLS_GlobalSetting]

    This query contains a property, called KnownVMMServer. This value should be the same as the value that you provided with the Set-DPMGlobalProperty cmdlet.

  4. Run the following query to validate the VMMIdentifier parameter in the PhysicalPathXML for a particular virtual machine:

    select cast(PhysicalPath as XML) from tbl_IM_ProtectedObject where DataSourceId in (select datasourceid from tbl_IM_DataSource where DataSourceName like '%<VMName>%')

  5. Replace VMName with the name of the virtual machine.

  6. Open the .xml file that this query returns and validate that the VMMIdentifier field has a value.

After completing configuration

After you set up DPM protection for live migration, you might want to complete a number of actions.

Manually run a live migration

After you completed the steps, live migration is enabled after the DPM Summary Manager job runs. By default, live migration starts at midnight and runs every morning. If you want to run a live migration immediately, you can run it manually as follows:

  1. Open SQL Server Management Studio and connect to the instance that hosts DPMDB.

  2. Run the following query: select * from tbl_SCH_ScheduleDefinition where JobDefinitionID=’9B30D213-B836-4B9E-97C2-DB03C3EB39D7’. Note that the query returns the ScheduleID.

  3. In SQL Server Management Studio, expand SQL Server Agent, and then expand Jobs.

  4. Right-click the ScheduleID that you noted, and select Start Job at Step.

Note that backup performance is affected when the job runs. The size and scale of your deployment determines how much time the job takes to finish.

Change the default DPM-VMM Helper service port

If you want to change the default port of 6070 that is used by DPM to host DPM-VMM Helper Service, do the following:

  1. Open the Registry Editor regedit.

  2. Navigate to HKLM\Software\Microsoft\Microsoft Data Protection Manager\Configuration.

  3. Create a 32-bit DWORD value, named DpmVmmHelperServicePort.

  4. Write the new port number as part of this registry key.

  5. Open <Install directory>\Microsoft System Center 2012\DPM\DPM\VmmHelperService\VmmHelperServiceHost.exe.config and change the port number from 6070 to the new port.

    For example: <add baseAddress="net.tcp://localhost:6080/VmmHelperService/" />

  6. Restart the DPM-VMM Helper service.

  7. Restart the DPM service.

Upgrade the VMM or DPM server

Note that if you upgrade the VMM management server, you must also upgrade the VMM console on the DPM server to maintain protection. If you upgrade DPM, set the Global Property on the DPM server for the KnownVMMServerName by using Windows PowerShell as follows: Set-DPMGlobalProperty -dpmservername <dpmservername> -knownvmmservers <vmmservername>

See Also

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For additional resources, see Information and Support for System Center 2012.

Tip: Use this query to find online documentation in the TechNet Library for System Center 2012. For instructions and examples, see Search the System Center 2012 Documentation Library.
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