Multipath I/O Installation on Windows 2008 R2 Server Core

To determine if the Multipath I/O feature has been installed, login to your core server and run oclist.exe:

If you already know the name of the feature or role your looking for, you can save yourself some time by piping the output of the oclist.exe command to the find.exe command. The /I parameter makes the search case insensitive.

To install the MultipathI/O feature, run “start/w ocsetup.exe MultipathIo”. The name of the feature is case sensitive. Running Start/W in front of the “OCSetup.exe” command will allow the installation to complete before you’re returned to a command prompt.

Run mpiocpl.exe:

Click on the “Discover Multi-Paths” tab, check the “Add support for iSCSI devices”, and click “Add”:

Reboot when prompted:

Run “mpclaim.exe –s –d” to verify multipath connectivity:

If a disk is not showing up, verify it is set to use “MPIO” in iscsicpl:

More details about iscsicpl can be found in my previous blog on “iSCSI Initiator Configuration on Windows 2008 R2 Server Core

If everything else is set correct and the device still does not show up, run “mpclaim.exe –e” to display the detected storage systems:

The load balancing policy can also be changed with the mpclaim.exe command. The default policy is “Round Robin”.

April 16, 2011
If you’re using an EqualLogic SAN, I recommend installing the EqualLogic Host Integration Tool (HIT) Kit before doing any of the Multipath I/O configuration. See my “MultiPath I/O on Server Core with the EqualLogic HIT Kit” blog for more information.



  1. Julien

    Hi Mike,

    I just set up an Hyper V configuration like yours.
    Two Dell servers, Dell switches 6224 and an Equallogic PS4000xv.
    Multipathing IO, Jumbo frame mtu 9000, Failover Cluster, Raid 6, several LUNs and so on.
    Everything is working fine (especially the liveMigration).
    Anyway when i tryed to copy/paste a VHD I had some question about the transfert speed. I tried many things but the current event is like :
    200MB/sec at the beginning and it fall and stay around 50MB/sec.
    I am just copying a big file on the same lun :/
    I read that it is normal and due to the Iscsi initiator of Microsoft.

    What do you think about that ?


    Julien From France

  2. Daniel Clarke

    Hi Mike,
    Im trying to find the equvilant powershell/mpclaim command line to Add the discovered multi-paths (this is achieved using the UI ‘Add’ button on the ‘Discover Multi-Paths’ tab.
    Do you know what this might be?

  3. Daniel Clarke

    fyi found the command, it was
    mpclaim.exe -r -i -a


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