Safety Net

Hyper-V Failover Cluster Setup

Installing a Windows Server 2016 Hyper-V failover cluster is not rocket science. Microsoft has simplified the steps with each version of Windows so that even inexperienced administrators can install a failover cluster. Because the VMs in a failover cluster must be reachable by all cluster nodes, shared storage is necessary: It can be deployed, for example, via fibre channel, iSCSI, or SMBv3. For the example in this article, I will be using the iSCSI protocol to provide the LUN to the cluster shared volume (CSV) and the quorum (witness).

iSCSI storage can be provided by a special storage device, such as a Windows Storage Server or Windows Server 2012; to do so, you need to install the iSCSI Target Server role service with the help of Server Manager or PowerShell. In Server Manager, you navigate to File and Storage Services | iSCSI , click the Tasks drop-down, select New iSCSI Virtual Disk , and define the path to the virtual data medium.

When you create the iSCSI target, you need to define the virtual disk's name and size. You have the choice between storage media of fixed or dynamic size. Select the fixed size as the deployment type. In the next step, click the New iSCSI Target radio button, enter a name for the target, and add the future cluster nodes using the query initiator, MAC address, DNS name, or IQN.

The storage area network (SAN) is now available on the cluster nodes, so you can start the iSCSI initiator there. The question of whether to launch the iSCSI initiator permanently is posed on first launch. To confirm this question, click on the Discovery tab and Discover Portal and specify the IP address or DNS name of the iSCSI target server (Figure 3). The iSCSI targets should now appear in the Targets tab. Click Connect and open a permanent connection to the iSCSI target. If the target can be reached by multiple paths, also enable the multipath I/O (MPIO) functionality. Install the MPIO software from the storage manufacturer in advance if the Microsoft's proprietary MPIO software is not sufficient.

Figure 3: Configuring the iSCSI target server and connecting the LUN through the iSCSI initiator.

Now enable the new volumes on just one cluster node in the disk manager, initialize the disks, and format them. You will want to initialize the disk for CSV with the GPT format; the quorum disk can be initialized with a master boot record (MBR). Format the quorum disk with NTFS and the default block size. The CSV disk needs to be formatted with the Resilient filesystem (ReFS) and a maximum block size of 64KB.

Connecting in the Network

For trouble-free operation and performance in a Hyper-V failover cluster, you need to pay particular attention to configuring network cards. In a cluster, you need network cards for:

• the cluster heartbeat
• management functions
• live migration
• the iSCSI network
• a Hyper-V virtual switch

For increased performance and resilience, you can and should use additional network adapters, which you combine to create teams with the help of the load balancing and the failover (LBFO) feature in Windows Server 2012 or newer.

The network card should have a throughput of at least 1Gbps; 10Gbps or higher is preferable. If you use network adapters with a throughput of 10Gbps or higher, you can add them to an LBFO team and then break them down into additional adapters using Hyper-V's virtualization feature. This reduces the cabling overhead and gives you additional options, such as bandwidth limitation. For further information on configuring network cards in Windows Server, see the checklist on TechNet [1].

After you have configured the network configuration identically on all future cluster nodes, you can install the failover cluster feature on both nodes and then launch cluster validation on one cluster node. Validation tells you whether the hardware and software configuration of the cluster nodes is suitable for clustering. The cluster validation must complete correctly before you can seek support from Microsoft.

Validating the Configuration

Select both cluster nodes and click the Run all tests (recommended) radio button. If cluster validation is successful, you can then create the cluster. The cluster needs to have its own NetBIOS/DNS name and an IP address from the LAN. Set these and continue with the configuration. After a short time, the cluster should have been created. Now check whether a computer object was created in Active Directory and the appropriate DNS A record was added in the DNS Manager of the DNS server.

Now, some granular adjustments to the cluster configuration are required to identify the individual components uniquely (e.g., network adapters and, later, LUNs). First, check whether the correct LUN has been configured as the quorum by clicking on Storage | Disks below the cluster object in the Failover Cluster Manager. Now the quorum LUN should be listed under Disk Witness in Quorum . Click on the properties of the quorum LUN and change the Name to Quorum in the General tab.

Make sure you have a unique description and unique functionality for the network cards. Click on Networks in the Failover Cluster Manager, right-click a network, choose Properties , and assign a unique name. Now check whether the intended use of the network card is entered correctly. The Live Migration and Heartbeat NICs should have only Allow clients to connect through this network enabled as functions, and the card for management should have only Allow cluster network communication on this network .

To enable the network for live migration, right click on the Networks | Live Migration Settings node and push the Live Migration network card up to the top. If necessary, remove the other network adapters from the setting.

In the next step, you will be assigning the CSV LUN to the cluster shared volumes in the Failover Cluster Manager by selecting the CSV LUN node (Storage | Disks ) and, under Actions, clicking Add to Cluster Shared Volumes . Then, launch the File Explorer on a cluster node, navigate to C:\ClusterStorage, and change the LUN name from Volume1 to a unique name before you install the first VMs.