•Use non-blocking switches, and set Configure Network Port Speed to a specific value rather than allowing speed negotiation.
•Disable the unicast storm control. Most switches have unicast storm control disabled by default. If your switch has unicast storm control enabled, you should disable it on the ports that are connected to the iSCSI Initiator hosts and targets to avoid packet loss.
•Use MPIO to manage multiple network connections to the storage in the iSCSI Initiator. This provides additional redundancy and fault tolerance on Windows Server operating systems.
•Enable flow control on network switches and adapters. Flow control ensures that a receiver can pace the sender’s speed, and it is important in avoiding data loss.
•Turn off the spanning tree algorithm for detecting loops. Loop detection introduces a delay in creating a port that can become usable for data transfer, and it can lead to application timeouts.
•Segregate SAN and LAN traffic. SAN interfaces in the iSCSI Initiator should be separated from other corporate network traffic (LAN). Servers should use dedicated network adapters for SAN traffic. Deploying traffic for the iSCSI Initiator on a separate network or networks helps minimize network congestion and latency. Additionally, traffic for the iSCSI Initiator is more secure when SAN and LAN traffic can be separated by using port-based virtual local area networks (VLANs) or physically separate networks.
•Configure additional paths for high availability. Use MPIO or multiple connections per session (MCS) with additional network adapters in the server. This creates additional connections to the storage array in the iSCSI Initiator through redundant Ethernet switch fabrics.
•Unbind File and Print Sharing from the iSCSI Initiator network adapters that connect only to the iSCSI Initiator SAN.
•Use an Ethernet connection that is a gigabit or faster for high-speed access to storage. Congested or lower-speed networks can cause latency issues that disrupt access between the iSCSI Initiator and applications for devices that are connected through the iSCSI Initiator. In many cases, a properly designed IP SAN can deliver better performance than internal hard disk drives. Microsoft iSCSI Initiator is suitable for WAN and lower-speed implementations, including replication where latency and bandwidth are not a concern.
