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Sunday, December 6, 2009

Small MPxIO tip

This is a relatively undersized tip however equally important on MPxIO.

I was always wondering on how to know that MPxIO is running/enable or not and what all kernel modules it loads when it is enabled and how to identify if MPxIO is enable using MPxIO kernel module.

One way that you can tell if your MPxIO enable or not is -

# stmsboot -L

If MPxIO is not enabled then this command returns message that MPxIO is not enabled which is very straight forward & then using stmsboot –e command to enable to MPxIO, BTW which is always followed by reboot.

Yet another way to know if MPxIO is enabled or not is -

# modinfo |grep -i vhci
22 1338650 15698 189 1 scsi_vhci (SCSI VHCI Driver 1.57)

If this module is loaded then it means MPxIO is running.


  1. Hi Nilesh,

    How do you interpret the following?

    root@my-sun-blade -> stmsboot -L
    stmsboot: MPxIO is not enabled
    stmsboot: No STMS devices have been found

    root@my-sun-blade -> modinfo | grep -i vhci
    23 fffffffffbbba5a0 16da0 174 1 scsi_vhci (SCSI VHCI Driver 1.57)


  2. Hi Supun,

    If scsi_vhci kernel module is loaded then storage multipathing is enabled & in your case yes, MPxIO is running.

    Verification needs to be done -

    Which storage vendor?

    What is the output of below commands -

    # uname -a

    # modinfo | grep mpxio

    # modinfo|grep fc

    # cat /kernel/drv/scsi_vhci.conf <<<< do you have defined mpxio-disable=no

    If Solaris 10
    # cat /kernel/drv/fc.conf <<<< do you have defined mpxio-disable=no

    Try enabling MPxIO again with -

    # stmsboot -D fp -e

    NOTE: Be careful with this command as this command ask for reboot.