"My Query is whether there will be any perf issue if one more disk enclosure is added to the controller as now i am clear that EVA 3K will not support more than 2 controller."
You probably will not experience any perf issues as the controllers were built to handle up to 4 shelves/56 fibre drives. Though, depending on how hard you expect to be hitting the controllers with I/O from the Exchange box, you can experience issues if you do not have enough drives to handle the i/o properly.
"I also have the option of getting a MSA 1000 storage and configure the exchange thro DAS . Can anyone please advice on which will be the better option."
The MSA is a SAN Storage Array and thus, is NOT DAS... Direct Attached Storage. I would go with 2 extra 5414 disk shelves for the EVA.
As for the ports on the back, all you do to add the 2 extra shelves is connect the the new shelves into the existing loop. Looking at the back of the EVA, you should see 2 loops. The loops starts at one controller, goes to the first shelf down, then that shelf is connected to the next shelf down, then that shelf is connected back up to the other controller. The second loop is similar, but generally reversed... starting at one cotroller, going to the very bottom disk shelf, then up to the next and finally back to the other controller.
Steven
Steven Clementi
HP Master ASE, Storage, Servers, and Clustering
MCSE (NT 4.0, W2K, W2K3)
VCP (ESX2, Vi3, vSphere4, vSphere5, vSphere 6.x)
RHCE
NPP3 (Nutanix Platform Professional)
