SC4020 Multipathing help

Hi All,

Just recently setup a new SC4020 compellent and R730xd server. This will be part of a bigger network but at the moment I'm testing failover and redundancy and just trying to get my head around Virtual Ports and MP.

Current test environment comprises of a Compellent SAN, 2 Fibre Switches, Ethernet Switch and 1 x hypervisor. My cabling is identical to this minus second hypervisor (hopefully photo posts okay) - Page 39 of the Owners Manual "Two iSCSI networks with Dual 2 port storage controllers"

I wanted to verify our environment just to ensure I've correctly set it up. I have simulated a controller restart and switch failure and have successfully kept a datastore online which I am happy about, however there is some behaviour I am experiencing with the iSCSI mappings that I don't feel is consistent with the intended design. 

ESXi 6.0 Server with 25GB iSCSI volume mapped in Storage Centre

iSCSI Initiators in vSphere: 10.1.1.4:3260 and 10.1.1.5:3260

Fault Domain 1 Controller IP: 10.1.1.4

Fault Domain 2 Controller IP: 10.1.1.5

VMKernel1: 10.1.1.2 (mapped to vmnic0)

VMKernel2: 10.1.1.3 (mapped to vmnic1)

• We have 1 x 25GB iSCSI data volume mapped to a ESXi hypervisor. ESXi Hypervisor has 2 x NICS configured with 2 x VMkernel adapters and appropriate binding and iSCSI settings connected (as per VMware Best Practices). Physical cabling is identical to above.
• iSCSI target set to 10.1.1.4 (FD1) and 10.1.1.5 (FD2). This gives paths of 10.1.1.10 and 10.1.1.11 which are the interfaces on the top controller. I browse to my test iSCSI datastore and upload a 5GB file and then disconnect power to Switch 1. The path still remains as 10.1.1.11 is on FD2 on Switch 2.
• The copy continues, slows down for awhile but eventually finishes. 

My questions:

- What should happen if I disconnect 10.1.1.11? At the moment if I disconnect 10.1.1.11 the iSCSI datastore drops connectivity. I would have thought the last port 10.1.1.13 (which is Bottom Controller Port 2 - Fault Domain 2) would pick up this path and continue to function?

- If I look at the multipathing paths in vSphere they all report as Dead and there is no mapping to 10.1.1.13 despite having both Fault Domains listed under the Dynamic Discovery tab . Further to this if I connect to the Compellent web management console and check my Hypervisor it lists the last controller port as active/available but if I change over to the Mapping tab it still only lists it doesn't list the controller port.

At the moment I'm trying to ascertain if I've set something up incorrectly? Or am I asking too much from the device, perhaps its not intended to be used like this? Multipathing is set to Round Robin in vSphere.

Any help would be really appreciated.

Kind Regards,

Cameron