I build up one iSCSI with MPIO in my lab, attached is draft diagram. My MPIO may not configure as well, due to even though I set Round Robin in my Windows Server 2012 iSCSI manager, I still noticed that only one NIC have traffic in the same time, and if I try to disconnect one cable, another cable will take around 30sec to get back on line.


Storage: HP P2000
Switch: CISCO 4900
Server: HP Bl460c g7
O.S: Windows Srv 2012 Data Center
Server NIC1 IP address: 
Server NIC2 IP address:
HP P2000 Controller A NIC1 IP:
HP P2000 Controller B NIC1 IP:


  • Your diagram is a bit off, you have it drawn so that two servers are sharing one switch port, which is not possible. Should it read "VLAN" on port3 and port4? Do you have VLANS configured? – pauska Sep 2 '13 at 7:29

Unless you have a symmetrical active/active array (which you do not), you can't have a single LUN active across two controllers.

If you want to have two paths active per LUN then you'll need to connect two ports per controller, like this:

(port numbers on switches and vlan numbers are imaginary, adjust to your environment)

  • ControllerA p0 -> switch p0 (VLAN100) - IP
  • ControllerA p1 -> switch p2 (VLAN101) - IP
  • ControllerB p0 -> switch p1 (VLAN100) - IP
  • ControllerB p1 -> switch p3 (VLAN101) - IP

One more thing - I strongly advice you to use two switches. Having a single switch means SPOF (Single Point Of Failure) - you don't want your entire environment to stop because of a single switch going down.

If you were to connect it to two switches, the layout would be like this:

  • ControllerA p0 -> switch1 p0 (VLAN100) - IP
  • ControllerA p1 -> switch2 p0 (VLAN101) - IP
  • ControllerB p0 -> switch1 p1 (VLAN100) - IP
  • ControllerB p1 -> switch2 p1 (VLAN101) - IP
  • I will have a try, then feedback to you. – siyang Sep 3 '13 at 3:14
  • Hi Pauskam, I have added ControllerAP1 and ControllerBP1, then I could see two iSCSI traffic NICs have the same data flow. But I tried to disconnect ControllerA P0 cable, still need use 30sec to change to another LAN. Is that I still use wrong configuration on O.S layer? – siyang Sep 3 '13 at 6:43

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