The best option to make this work is using NFS connected to the Vsphere 5.x cluster.  Here is the suggestion that I made VMware has a limit of 2TB VMDK files that can be presented to a host regardless of protocol ie FC, iSCSI Customer had a requirement of at least 10TB volume to archive the content  On the cluster create multiple 2TB controlled SmartQuota managed NFS shares mapped to the ESX server.  In this case a minimum of 5.  I liked the idea of using a multiple of the number of nodes in the cluster for this case was 3 nodes X200.  So make 6 NFS shares presented to the ESX server.  Make the NFS shares available to the guest OS system by creating the multiple VMDK files and presenting them under VMware.  Leverage Windows disk manager inside server 2012 and create a dynamic disk with all the VMDK's present and then you have your large single volume presented to windows with multiple NFS mount points hitting multiple nodes on the Isilon cluster to balance and maximize performance.
I had a customer looking for block storage (iSCSI) support from their Isilon cluster as they had a Windows guest VM which required block storage access to satisfy and application.  In this case the application was Lotus notes.  Collecting perstats from the Windows guest system showed the IO rate, size and latency that the current application was experiencing.  What's the best way to leverage the Isilon cluster for this storage requirement.
How can I provide effective block storage to a VMware guest system?