After installing DELL Storage SC 3020 with microsoft Hyper-v virtualization system I had terrible performance issue when copying files from the CSV to the host, Seems that all the file transfare between the host and the storage is extremely slow . and we could see it in the storage charts on the latency section. normally it is below 1. on the copying period it was around 100
After hour of investigation I found out that on the ISCSI switch, the ports was configure with flow control = off . After turning the flow control to auto the latency went down and the speed was improving by far !
In addition you have to make sure that in the cluster networks, you assign the right role to the network subnet