Thanks Peter for your valuable response!
-No background job was taking CPU/IOPS
-Need to check (Is looking client connection on dashboard of Management UI is right way?We are using smartconnect (with basic licence, I think , it is round robin policy)
-we did mount NFS on compute node using rsize=131072,wsize=131072 (need to check whether negotiated value is also 128k)
-we did setting in management UI, can you suggest ways to check whether it is really in effect or not?
-Need to check it (will update you once it is done)