Configuring networking - iSCSI VMware

You can set up your iSCSI network in many ways, depending on your data storage requirements.

Consult your network administrator for tips on selecting the best configuration for your environment.

While planning your iSCSI networking, remember that the VMware Configuration Maximums guides state that the maximum supported iSCSI storage paths is 8. You must consider this requirement to avoid configuring too many paths.

By default, the VMware iSCSI software initiator creates a single session per iSCSI target when you are not using iSCSI port binding.

Note: VMware iSCSI port binding is a feature that forces all bound VMkernel ports to log into all target ports that are accessible on the configured network segments. It is meant to be used with arrays that present a single network address for the iSCSI target. Lenovo recommends that iSCSI port binding not be used. For additional information, see the VMware Knowledge Base for the article regarding considerations for using software iSCSI port binding in ESX/ESXi. If the ESXi host is attached to another vendor's storage, Lenovo recommends that you use separate iSCSI vmkernel ports to avoid any conflict with port binding.

To ensure a good multipathing configuration, use multiple network segments for the iSCSI network. Place at least one host-side port and at least one port from each array controller on one network segment, and an identical group of host-side and array-side ports on another network segment. Where possible, use multiple Ethernet switches to provide additional redundancy.

You must enable send and receive hardware flow control end to end. You must disable priority flow control.

If you are using jumbo frames within the IP SAN for performance reasons, make sure to configure the array, switches, and hosts to use jumbo frames. Consult your operating system and switch documentation for information on how to enable jumbo frames on the hosts and on the switches. To enable jumbo frames on the array, complete the steps in Configuring array-side networking—iSCSI.

Note: Many network switches have to be configured above 9,000 bytes for IP overhead. Consult your switch documentation for more information.