This disk is offline because of policy set by administrator

clusterhyper-vwindows-server-2008

I have a IBM NAS based storage interfaced using iSCSI interface on my two node Hyper – V Cluster on Windows Server 2008 R2.

I am in process of setting up this cluseter. All tests have passed according to Validate Cluster report.

I can see Both the disks as online simultaneously on both nodes. However, as soon as I add the disk to the cluster usind "Disks -> Add Disk", it becomes available to only one host. The other hosts shows "This disk is offline because of policy set by administrator" in its Disk Management. I can alternate this situation by choosing "Disk->Make this resource available to Node2" , but then it becomes available to Node2 and the same message is shown Node 1 in Disk Management.

Is this correct ?

As per my understanding, I should be able to see both disks online even after adding it as clustered Disk. How will the both nodes operate their VM if disk is not make available to both the nodes.

Best Answer

Make sure you have Cluster Shared Volumes enabled. From this link:

A feature of failover clusters called Cluster Shared Volumes is specifically designed to enhance the availability and manageability of virtual machines. Cluster Shared Volumes are volumes in a failover cluster that multiple nodes can read from and write to at the same time. This feature enables multiple nodes to concurrently access a single shared volume. The Cluster Shared Volumes feature is only supported for use with Hyper-V and other technologies specified by Microsoft.

On a failover cluster that uses Cluster Shared Volumes, multiple clustered virtual machines that are distributed across multiple cluster nodes can all access their Virtual Hard Disk (VHD) files at the same time, even if the VHD files are on a single disk (LUN) in the storage. This means that the clustered virtual machines can fail over independently of one another, even if they use only a single LUN. When Cluster Shared Volumes is not enabled, a single disk (LUN) can only be accessed by a single node at a time. This means that clustered virtual machines can only fail over independently if each virtual machine has its own LUN, which makes the management of LUNs and clustered virtual machines more difficult.

For a two-node failover cluster, the storage should contain at least two separate volumes (LUNs), configured at the hardware level. Do not expose the clustered volumes to servers that are not in the cluster. One volume will function as the witness disk (described later in this section). One volume will contain the files that are being shared between the cluster nodes. This volume serves as the shared storage on which you will create the virtual machine and the virtual hard disk. To complete the steps as described in this document, you only need to expose one volume.

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