VMware iSCSI host attachment

iSCSI Ethernet hosts for the VMware operating system can be attached to FlashSystem.

Before you begin host attachment procedures:
  • Read the information about setting up the host server.
  • Ensure that you are familiar with the command-line interface (CLI) commands.

Installing the VMware initiator software

The following example shows the VMware ESXi 8.0 host configuration. Ensure that the supported release of the initiator software is installed on your host before you proceed.

Complete the following steps to install the VMware initiator software:
  1. Enter the IP address of the ESX server, user ID, and password to log in to the system.
    Note: Use the default initiator SCSI settings.
    The following functions are not supported:
    • Guest OS support
    • SAN boot support
    For more details on support metrics, see IBM System Storage Interoperation Center (SSIC).
  2. Prepare an iSCSI network: Create a dedicated VLAN or subnet and ensure end‑to‑end MTU consistency if you are using jumbo frames. For details, see Best practices for running VMware vSphere on iSCSI network.
  3. Configure a vSwitch for iSCSI: Create a dedicated standard vSwitch with one physical NIC per iSCSI path. For details, see Create a vSphere standard Switch.
  4. Create iSCSI VMkernel adapters: Create a VMkernel per iSCSI path and enable iSCSI traffic. For details, see Create a VMkernel adapter.
  5. Enable VMware iSCSI software adapter: Add and enable the software iSCSI adapter on the ESXi host. For details, see Add or remove the software iSCSI adapter.
  6. Bind VMkernel adapters to the iSCSI adapter: Bind all iSCSI VMkernels for multipathing. For details, see Configure port binding for iSCSI or iSER on ESXi.
  7. Disable iSCSI delayed ACK: Disable DelayedAck on the iSCSI adapter to avoid storage latency issues. Host restart is required after you change the DelayedAck settings on the ESXi host. For details, see ESX/ESXi hosts might experience read or write performance issues with certain iSCSI storage arrays.
  8. Add IBM Storage FlashSystem iSCSI targets: Add FlashSystem target IPs by using the Dynamic Discovery. For details, see Configure dynamic or static discovery for iSCSI and iSER on ESXi host.
    Note: If you remove the target IP on the Dynamic Discovery tab, then all target portals are removed.
  9. Set up CHAP for iSCSI Storage Adapters (optional): You can set up unidirectional (one-way) and bidirectional (two-way) CHAP authentication for VMware hosts.
    To set up unidirectional (one-way) and bidirectional (two-way) CHAP authentication on a VMware host, complete the following steps:
    1. From the vSphere Client page, select Inventory tab.
    2. Select Storage Adapters > iSCSI storage adapter, and then right-click and select Properties.
    3. Select CHAP authentication.
    4. Select the preferred settings and enter the password:
      1. From the CHAP target authenticates host menu, select Use CHAP.
      2. Select Use initiator name to use IQN of the initiator as the username for CHAP authentication or enter the username that you set with the chhost CLI command hostusername field on the system. Enter the CHAP secret.
    To set up the bidirectional (two-way) authentication, repeat the preceding procedure from this step and then complete the following steps:
    1. From the Mutual CHAP authentication menu, select Use CHAP.
    2. Select Name and enter the storage_username value that can be found by lshost command.
    3. Enter CHAP secret. Ensure that the CHAP secret matches the value that configured with the chhost command.
    Note: If you configure two-way CHAP authentication before you upgrade to software version 8.5.3.0, then switch to the one-way CHAP first and then back to two-way CHAP after the upgrade is complete. This switch is required because clustername as a username is not supported for the two-way CHAP secret in older releases.
  10. Rescan storage adapters to discover iSCSI LUNs from FlashSystem.
  11. Present storage to VMs: Create VMFS datastores or use RDM for direct LUN access. For details, see Best practices for running VMware vSphere on iSCSI.
  12. Set a multipathing policy: Configure all iSCSI devices to use Round Robin for optimal load balancing. VMware supports different types of multiple paths.
    1. Round Robin: VMware accesses different paths available at fixed intervals.
    2. Fixed path: The I/O initiates access from the path that is initially selected, and switches to a different path if problems are encountered.
    3. Most recently used path: VMware uses the most recently used path, and switches to a different path if problems are encountered.

Viewing available paths

To view available paths in VMware, complete the following steps:

  1. In the vSphere Client, go to the ESXi host > Configure.
  2. Under Storage > Storage Devices, select the storage device whose paths you want to view.
  3. On the Properties tab and review the module that owns the device, such as NMP or HPP. Under Multipathing Policies, you can also view the Path Selection Policy and the Storage Array Type Policy assigned to the device, if applicable.
  4. On the Paths tab. Review all paths available for the storage device and the status of each path. The following path status information appears:
    Table 1. Path status information
    Status Description
    Active (I/O) Indicates a working path or multiple paths that currently transfer the data.
    Standby Indicates paths that are not active. If the active path fails, standby paths become operational and start I/O transfer.
    Disabled Indicates paths that are deactivated by the administrator.
    Dead Indicates paths that are no longer available for processing I/O. A physical medium failure or array misconfiguration can cause this status.
    Note: If you are using the Fixed path policy, you can see the preferred path, which is marked with an asterisk (*) in the Preferred column.

    For more details, see Viewing and managing storage paths on ESXi hosts.