It have to be the lowest VMK # of all your iSCSI ports, so you have to remove the 2 existing VMKs first and start from scratch.  Reason is that vSphere use the lowest one to try the access the array when discovering/scaning the volumes on the EQL. If this pNic, Cable, pSwitch goes down and you press the Rescan button within vSphere you get into trouble.

With vSphere 5.1 this is not necessary any more so you may consider and upgrade to the latest version.

Regards,

Joerg

I've been told that as of ESXi 5.1.0 the storage heartbeat is no longer needed due to a change in how ESXi responds to pings or so.

Thanks for the quick response. Rather than delete both existing iscsi vmk ports on the switch, would unbinding and deleting the existing lowest port i.e ISCSI1/vmk1 , add the heartbeat port as vmk1, then recreating ISCSI and rebinding  it  work? That would seem to maintain SAN access throughout

I currently have two PE R910's connected via stacked PC 6224's to an EQL PS4100X.

My vSwitch for iSCSI was originally configured by Dell PRIOR to vSphere 5.1 as follows:

Both hosts are configured the same.

Network Adapters: vmnic4 and vmnic5

vSwitch

* MTU 9000

* Active Adapters vmnic4, vmnic5

* Load Balancing: Route based on the originating virtual port ID

VM iSCSI Network

* Active Adapters vmnic4, vmnic5

iSCSI2

* MTU 9000

* Active Adapter vmnic5

* Active Adapter vmnic4

iSCSI1

* MTU 9000

* Active Adapter vmnic4

* Active Adapter vmnic5

Storage Heartbeat

* MTU 9000

* Active Adapters vmnic4, vmnic5

With the enhancements provided in vSphere 5.1 is it safe to simply delete the SHB VMKernel port on each host?

My apologies, that was a typo.  On iSCSI2 vmnic5 is active while vmnic4 is unused.  On iSCSI1 vmnic4 is active while vmnic5 is unused.

Thank you for the quick response!  Also thank you for the other information you've posted within the forum relating to setting LRO to zero, changing settings with respect to Round Robin, etc.