HYPER-V iSCSI with multi-path to the SAN RRS feed

  • Question

  • Hi all,

    I have setup an environment like this:

    - Host Server : Dell PE610 server with 8 NIC running 2008 R2 datacenter Edition

    - SAN : Equalogic PS4000X

    - "iSCSI network": 2 switch, for multi-path

    The host server works fine, and the SAN is well initiated (IP, LUNs etc...).
    With the technician off DELL, we setup the iSCSI in multi-path to a LUN used to store the VHD files.
    This one work fine, I can unplug a network path and the iSCSI take the other path.

    I'm running HYPER-V on the host server. No cluster as I don't have another server yet (next fiscal year).

    I have to run a file server in a virtual machine, Running 2003 server.
    note: I'm familiar with virtual server (2005 on windows 2003) since few years, but this is my first experience on Hyper-V.
    I have use a VHD file of a fresh Windows 2003, removed add-in (2005 virtual server) and installing the one off Hyper-V.

    I have setup 3 networks card of the host server to be shown in the VM:

    1. Virtual Network LAN : Go to our LAN.

    2. Virtual Network iSCSI : Go to the "iSCSI network", use as the primary PATH to the SAN.

    3. Virtual Network iSCSI2 : Go to the "iSCSI network", failover PATH to the SAN.

    I have installed the iSCSI initiator from Microsoft, setup the connection to the LUN used for the file server (shared data).
    Log on twice to use the multipath, setup this one as failover. I can see both connection initiated on the SAN reports.

    Everything works fine, and looks fine if I desactivate a network card in my VM, the drive switch to the other PATH like a charm.

    But if I test an hardware issue (unplugg a network path) the multipath doesn't work, the DRIVE disapear or can't be writen anymore.
    The status on the iSCSI show that the PATH 1 is still working ?
    I realize that the VM is not aware of the network cable unplug, the network cards is still showing a 10gbs connection running?!
    So that's normal that the iSCSI iniator don't manage the failover, as there is no issue for the VM windows 2003 !!!



    1. How can I setup HYper-V to transmit the "cable unplug" information to the VM ?

    2. Is my overview correct ? Or am I not in looking in the good direction?
    Is there another way to manage the multi-path (let say redundancy of the PATH)?
    e.g.: "grouping 2 networks cards of the host, use different paths to the SAN, show them as ONE CARD on the VM..."


    Thanks for your help.

    Happy new year, Yannick.


    ps: first topic here, a question ! ;) but you will here from me, and I will share my experience when I will get some.








    Thursday, December 30, 2010 11:02 AM

All replies

  • Hi Yannick!

    Your 3 virtual NIC's aren't connected to the physical NIC's directly, they are connected to virtual switches created by the Hyper-V host. So if you unplug one of the cables the VM is still connected to the "network" even though it can't reach anything outside the host.

    The best way to configure the SAN in your case, would be to do it on the host and make sure that the VM can always reach it's vhd's. In that way the virtual machine will always be running and totally unaware if a path breaks.

    / Ogge


    • Proposed as answer by Mike_Andrews Wednesday, January 5, 2011 3:26 PM
    Wednesday, January 5, 2011 3:25 PM