A dependent hardware iSCSI adapter in your ESXi system is a third-party adapter that depends on VMware networking, and iSCSI configuration and management interfaces provided by VMware.

An example of a dependent iSCSI adapter is a Broadcom 5709 NIC. When installed on a host, it presents its two components, a standard network adapter and an iSCSI engine, to the same port. The iSCSI engine appears on the list of storage adapters as an iSCSI adapter (vmhba).

The iSCSI adapter is enabled by default. To make it functional, you must connect it, through a virtual VMkernel adapter (vmk), to a physical network adapter (vmnic) associated with it. You can then configure the iSCSI adapter.

After you configure the dependent hardware iSCSI adapter, the discovery and authentication data is passed through the network connection. The iSCSI traffic goes through the iSCSI engine, bypassing the network.

The entire setup and configuration process for the dependent hardware iSCSI adapters involves several steps.

Step Description
View Dependent Hardware iSCSI Adapters View a dependent hardware iSCSI adapter to verify that it is correctly loaded.
Modify General Properties for iSCSI or iSER Adapters on ESXi Hosts If needed, change the default iSCSI name and alias assigned to your adapter.
Determine Association Between iSCSI and Network Adapters You must create network connections to bind dependent iSCSI and physical network adapters. To create the connections correctly, determine the name of the physical NIC with which the dependent hardware iSCSI adapter is associated.
Configure Port Binding for iSCSI or iSER on ESXi Configure connections for the traffic between the iSCSI component and the physical network adapters. The process of configuring these connections is called port binding.
Configure Dynamic or Static Discovery for iSCSI and iSER on ESXi Host Set up dynamic discovery. With dynamic discovery, each time the initiator contacts a specified iSCSI storage system, it sends the SendTargets request to the system. The iSCSI system responds by supplying a list of available targets to the initiator. In addition to the dynamic discovery method, you can use static discovery and manually enter information for the targets.
Set Up CHAP for iSCSI or iSER Storage Adapter If your iSCSI environment uses the Challenge Handshake Authentication Protocol (CHAP), configure it for your adapter.
Set Up CHAP for Target You can also configure different CHAP credentials for each discovery address or static target.
Enable Jumbo Frames for Networking If your iSCSI environment supports Jumbo Frames, enable them for the adapter.

Dependent Hardware iSCSI Considerations

When you use dependent hardware iSCSI adapters with ESXi, certain considerations apply.

  • When you use any dependent hardware iSCSI adapter, performance reporting for a NIC associated with the adapter might show little or no activity, even when iSCSI traffic is heavy. This behavior occurs because the iSCSI traffic bypasses the regular networking stack.
  • If you use a third-party virtual switch deactivate automatic pinning. Use manual pinning instead, making sure to connect a VMkernel adapter (vmk) to an appropriate physical 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, activate flow control to avoid performance degradation.

    Flow control manages the rate of data transmission between two nodes to prevent a fast sender from overrunning a slow receiver. For best results, activate flow control at the end points of the I/O path, at the hosts and iSCSI storage systems.

    To activate 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

  • Dependent hardware adapters support IPv4 and IPv6.

View Dependent Hardware iSCSI Adapters

On an ESXi host, view a dependent hardware iSCSI adapter to verify that it is correctly loaded.

If installed, the dependent hardware iSCSI adapter (vmhba#) appears on the list of storage adapters under such category as, for example, Broadcom iSCSI Adapter. If the dependent hardware adapter does not appear on the list of storage adapters, check whether it needs to be licensed. See your vendor documentation.

Procedure

  1. In the vSphere Client, navigate to the ESXi host.
  2. Click the Configure tab.
  3. Under Storage, click Storage Adapters.
  4. Select the adapter (vmhba#) to view.
    The default details for the adapter appear, including the iSCSI name, iSCSI alias, and the status.

What to do next

Although the dependent iSCSI adapter is enabled by default, to make it functional, you must set up networking for the iSCSI traffic and bind the adapter to the appropriate VMkernel iSCSI port. You then configure discovery addresses and CHAP parameters.

Determine Association Between iSCSI and Network Adapters

On an ESXi host, network connections bind dependent iSCSI and physical network adapters. To create the connections correctly, you must determine the name of the physical NIC with which the dependent hardware iSCSI adapter is associated.

Procedure

  1. In the vSphere Client, navigate to the ESXi host.
  2. Click the Configure tab.
  3. Under Storage, click Storage Adapters.
  4. Select the iSCSI adapter (vmhba#) and click the Network Port Binding tab under adapter details.
  5. Click Add.
    The network adapter (vmnic#) that corresponds to the dependent iSCSI adapter is listed in the Physical Network Adapter column.

What to do next

If the VMkernel Adapter column is empty, create a VMkernel adapter (vmk#) for the physical network adapter (vmnic#) and then bind them to the associated dependent hardware iSCSI. See Setting Up Network for iSCSI and iSER with ESXi.