vsphere-esxi-vcenter-server-55-storage-guide

Chapter 11 Configuring iSCSI Adapters and StorageThe entire setup and configuration process for the dependent hardware iSCSI adapters involves these steps:1 View the dependent hardware adapters.See “View Dependent Hardware iSCSI Adapters in the vSphere Web Client,” on page 80.If your dependent hardware adapters do not appear on the list of storage adapters, check whether theyneed to be licensed. See your vendor documentation.2 Determine the association between the dependent hardware adapters and physical NICs.See “Determine Association Between iSCSI and Network Adapters in the vSphere Web Client,” onpage 80.Make sure to note the names of the corresponding physical NICs. For example, the vmhba33 adaptercorresponds to vmnic1 and vmhba34 corresponds to vmnic2.3 Configure networking for iSCSI.See “Setting Up iSCSI Network,” on page 83.Configuring the network involves creating a VMkernel interface for each physical network adapter andassociating the interface with an appropriate iSCSI adapter.4 (Optional) Enable Jumbo Frames.See “Using Jumbo Frames with iSCSI,” on page 89.5 Configure discovery information.See “Configuring Discovery Addresses for iSCSI Adapters,” on page 90.6 (Optional) Configure CHAP parameters.See “Configuring CHAP Parameters for iSCSI Adapters,” on page 92.Dependent Hardware iSCSI ConsiderationsWhen you use dependent hardware iSCSI adapters with ESXi, certain considerations apply.• When you use any dependent hardware iSCSI adapter, performance reporting for a NIC associatedwith the adapter might show little or no activity, even when iSCSI traffic is heavy. This behavior occursbecause the iSCSI traffic bypasses the regular networking stack.• If you use a third-party virtual switch, for example Cisco Nexus 1000V DVS, disable automatic pinning.Use manual pinning instead, making sure to connect a VMkernel adapter (vmk) to an appropriatephysical NIC (vmnic). For information, refer to your virtual switch vendor documentation.• The Broadcom iSCSI adapter performs data reassembly in hardware, which has a limited buffer space.When you use the Broadcom iSCSI adapter in a congested network or under heavy load, enable flowcontrol to avoid performance degradation.Flow control manages the rate of data transmission between two nodes to prevent a fast sender fromoverrunning a slow receiver. For best results, enable flow control at the end points of the I/O path, atthe hosts and iSCSI storage systems.To enable flow control for the host, use the esxcli system module parameters command. For details,see the VMware knowledge base article at http://kb.vmware.com/kb/1013413• Broadcom iSCSI adapters do not support IPv6.VMware, Inc. 79