So if i get you right you a one volume wit a lun inside on the netapp. If you map the lun to the physical machine you get 1,5gb/s, if you map it to the esx and present it as a raw device to a vm you get 250mb/s.
In what mode have you configured the raw device, physical or virtual mode ?
Have you checked the hba´s on the esx regarding utilization, errors etc ?
sorry for my delayed answer but we are still investigate that issue.
Yes, you are right, Physical performance on same netapp is multiple times better than VM performance.
We have checked both. pRDM and vRDM and also VMFS.
Any updates? I'm experiencing similar situation but we're using BL460c (in C7000)<->Brocade 8 Gb<->3PAR 7400.
On bare metal W2K12 I've got 1500 MBps with Crystal DiskMark and about 450 MBps with file copy.
On ESXi I've got about 130 MBps no matter inside VM or directly from HV.