I am afraid you are completely misunderstanding how the EqualLogic product works.
If I understand your setup correct you are using 1 ESX server with 4 NICs for exclusive iSCSI traffic.
You are also using 1 PS6000.
Server as well as storage are connected via 2 switches.
A SAN should always be a dedicated network just for storage data. Hence you are correct about using a dedicated LAN segment for iSCSI traffic.
It is also critical for performance that traffic will not go via a router.
To achieve a multipathed connection between an ESX server and a storage device multiple iSCSI sessions must be established using multiple VMkernels and the ESX can then use round robin multipathing.
So far so good.
Most storage products that support multipathing will present an iSCSI target via different controller ports and for multipathing to work you must establish an iSCSI session to each controller IP address involved.
That is NOT the case with an EqualLogic array. EqualLogic arrays are a virtualization approach completely hiding the physical array NICs behind a virtual group IP. The group IP is up on one of the array ports but NOT on all of them. It will switch to another array NIC should that become necessary. To establish an iSCSI session you must always connect to the group IP only. The array will then decide (load balancing) which of its physical NIC should take that session. That NIC will then answer with an iSCSI redirect and tell the ESX server to connect to its IP address instead of the group IP. You should NEVER open an iSCSI session to any other IP than the group IP. Also there is no way for you to force a connection to a certain storage NIC!
The array itself has an active and a passive controller. The active controller can be configured with up to 4 NICs for iSCSI traffic. The passive controller will take over these connections should the active controller fail. All 4 NICs on the active coontroller support active/active multipathing.
For this whole mechanism to work every ESX NIC must be able to physically reach every array port. With a redundant switch setup both switches either MUST be stacked or they MUST be connected using an ISL with at least 4 GB bandwidth.
You can then create up to 4 iSCSI sessions from a maximum of 4 VMkernels (since you have 4 ESX NICs) using the group IP in every iSCSI session. By default ESX will create these as active/passive which you can change on the ESX server.
Hence you will never get more than 4 paths to an iSCSI target. Should you only use 2 iSCSI sessions you will only use 2 paths.
Hope this helps.
