iSCSI session terminated unexpectedly

We have SAN MD3200i on which it has total storage array of 6TB Hard disk (3 disks of 2TB each are placed in SAN).

And we are using Windows Server 2012 on which “Modular Disk Storage Manager” and “Hyper V Manager” is installed and from there we manage virtual machines.

Now we are getting many error of "iSCSI session terminated unexpectedly" and SAN is completely unstable and because of which SQl server and other services on Virtual machines are getting crashed.