.. _Accessing iSCSI Targets from Microsoft Hyper-V:

Accessing iSCSI Targets from Microsoft Hyper-V
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Before connecting an iSCSI initiator of Microsoft Hyper-V to iSCSI targets working in the ALUA mode, you need to install and configure Multipath I/O (MPIO). This feature can be used starting from Windows Server 2008 R2. To connect the initiator, for example, on Microsoft Hyper-V Server 2016, do the following:

#. Run Windows PowerShell with administrator privileges and install MPIO.

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      > Enable-WindowsOptionalFeature –Online –FeatureName MultiPathIO

   Your server will automatically reboot to finalize the installation.

#. In the Windows PowerShell console, configure MPIO as follows:

   #. Enable support for iSCSI disks:

      ::

         > Enable-MSDSMAutomaticClaim -BusType iSCSI

   #. Set the failover policy to Fail Over Only. The policy uses a single active path for sending all I/O, and all other paths are standby. If the active path fails, one of the standby paths is used. When the path recovers, it becomes active again.

      ::

         > Set-MSDSMGlobalDefaultLoadBalancePolicy -Policy FOO

   #. Enable path verification. By default, the initiator will verify each path every 30 seconds.

      ::

         > Set-MPIOSetting -NewPathVerificationState Enabled

   #. Reboot the server.

#. Connect your targets to the iSCSI initiator as follows:

   #. In the **Control Panel** > **System and Security** > **Administrative Tools** > **Services** window, make sure that **Microsoft iSCSI Initiator Service** is running and its startup type is set to **Automatic**.

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   #. Launch **iSCSI Initiator**.

   #. In the **iSCSI Initiator Properties** window, open the **Discovery** tab and click **Discover Portal**.

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   #. In the **Discover Target Portal** window, enter the target IP address and click **OK**. Repeat this step for each target from the target group.

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   #. On the **Targets** tab, click **Refresh** to discover the added targets.

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   #. Click **Connect** for each target to connect it to the initiator. In the **Connect To Target** window, select the **Enable multi-path** checkbox and click **OK**.

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   #. On the **Targets** tab, click **Devices..**, select the connected LUN, and click **MPIO..**.

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   #. Make sure the connected LUN has several paths.

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You can now initialize the newly added disk for use in Microsoft Hyper-V. Do the following:

#. Open **Disk Management**, right-click the added disk, and choose **Properties** from the drop-down menu.

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#. Check the settings on the **MPIO** tab. The first connected target becomes **Active/Optimized** and the preferred path. 

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#. Partition and format the disk as usual.

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