How to setup VNX for VMWARE performance

Hi,

i'm using Clariion 2 CX4-240 in DRP mode for exchange mailbox and ESX nodes. My clariion has only 2GB of cache and wich seems to be overloaded since several month.

On these clariion arrays i'm using  22x luns on Raid5 -8+1 600K 10k disks to hosts my VMs. i have seeing IOPS on each RG are very huge ( sometime more than 2500 IOPS ).

I can not acquire more DAE and disks on clariion arrays also I plan to acquire two VNX5300 dedicated only to my  ESX Farm ( 4 nodes perhaps 6 soon ).

What  is the best configuration that you suggest in term of raid setting on VNX (I don't know how pool works on VNX, if you can give me an explanation you're welcome?) .

I thought to acquire SSD + SAS 10k disk too , what do you think about this solution ?