I have 2 Dell R710 servers (intended to set up HyperV cluster) and a MD3000i SAN set up:


  • NIC 1: connected to company LAN
  • NIC 2: crossover to the other server's NIC 2
  • NIC 3: crossover to iSCSI port of SAN controller 1
  • NIC 4: crossover to iSCSI port of SAN controller 2

I have both servers setup as diskless servers with iSCSI boot from SAN without problem. But how can I access iSCSI from within the VM such that I can set up clustering inbetween the VMs? I can ping from the host to the SAN but found that NIC3/4 cannot be used for virtual network in HyperV? What am I doing wrong?

2 Answers 2


When you created the VM you assigned it to a virtual network. That virtual network, when created, was assigned to a physical NIC on the server. The VM can then only access the network(s) available to that physical NIC. My guess is given the NIC config of your hosts, you have the virtual network assigned to NIC 1 and since NIC 1 can't connect to the MD3000i, you're stuck.

If my assumptions are correct, the solution is to create two more virtual networks in Hyper-V. Assign one to NIC 3 and one to NIC 4. Then add two more NICs to the VM and connect one to each of those virtual networks and configure them with IPs in whatever range you're using for iSCSI.

If my assumptions are incorrect, post more info.

  • you assumption is correct but my problem is I cannot assign NIC3/4 to the virtual networks!? I can only select NIC1/NIC2 using the HyperV Manager mmc...
    – William
    Apr 22, 2010 at 0:53
  • Can you say a bit more about that? What kind of IP addressing are you using on those NICs? Do you have just an IP and subnet mask configured? And when you say you can't assign NIC3/4, you mean they just don't appear in the list of NICs to pick? I've never myself tried to create a virtual network on top of a NIC that is crossover-cable connected to storage like that. It's possible Hyper-V won't show a NIC that doesn't have a gateway or something like that and you'll need to get a switch involved.
    – icky3000
    Apr 22, 2010 at 7:28
  • Thank you icky2000 for your input. I think the problem was caused by the bootless setup. I have given up bootless setup and am trying to setup clustering VMs inside the HyperV cluster.
    – William
    Apr 22, 2010 at 16:08

I am answering my own question since I finally gave up on diskless setup. Once I installed physical HDs to the servers and install 2008 R2 locally, everything seem to start working as expected and I can use all 4 NICs inside HyperV manager. Perhaps there are some changes made by the BIOS/NIC when the machine is being booted from iSCSI, making them unusable by HyperV.

  • I tried diskless setup too and found it gave me a whole world of pain. If I remember correctly it seemed to lock the OS to only use a single NIC so it ignored the other path to the ISCSI SAN. Despite setting up MPIO, if you pulled a cable the OS crashed, and obviously the clustering didn't work properly. Boo May 10, 2012 at 13:07

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