You can use vSphere Lifecycle Manager images to perform firmware updates on the ESXi hosts in a cluster. Using vSphere Lifecycle Manager images simplifies the host update operation. With a single operation, you update both the software and the firmware on the host.
In earlier vSphere releases, you could perform firmware updates on vSAN clusters by using system-managed baselines. For non-vSAN clusters, firmware updates had to be manual.
Starting with vSphere 7.0, you can easily update the firmware in any cluster that you manage with a single image. Firmware updates are not available for clusters that you manage with baselines.
To apply firmware updates to the hosts in a cluster that you manage with a single image, you must include a special type of add-on, the firmware and drivers add-on, in the image and remediate the cluster to apply the image to all hosts. The firmware and drivers add-on is a vendor-provided add-on that contains the components that encapsulate firmware update packages. The firmware and drivers add-on might also contain the necessary drivers.
Unlike vendor add-ons, firmware and drivers add-ons are not distributed through the official VMware online depot or as offline bundles available at my.vmware.com. For a given hardware vendor, firmware updates are available in a special vendor depot, whose content you access through a software module called a hardware support manager. The hardware support manager is a plug-in that registers itself as a vCenter Server extension. Each hardware vendor provides and manages a separate hardware support manager that integrates with vSphere. For each cluster that you manage with a single image, you select the hardware support manager that provides the firmware updates for the cluster. After you determine the hardware support manager that you want to use for a cluster, the hardware support manager provides you with a list of the available firmware updates. When you select and include a firmware add-on to an image, that add-on might modify the specified image by adding or removing components. The firmware add-on also defines the firmware versions to be installed on the hosts. During remediation, vSphere Lifecycle Manager applies the image to the hosts and requests the selected hardware support manager to update the firmware on the hosts in accordance with the firmware add-on specified in the image.
Selecting a hardware support manager and including a firmware add-on in your image guarantees that during a compliance check, vSphere Lifecycle Manager also determines the firmware compliance for the cluster. So, you can easily detect and remediate any unwanted drifts. The hardware support manager is also responsible for retrieving the firmware versions on the host hardware, and, in some cases, determining the appropriate drivers for the updated firmware version.
For vSAN clusters, the hardware support manager inspects the hosts in the cluster to determine their current I/O device controllers and firmware. During a hardware compatibility check for the cluster, vSphere Lifecycle Manager checks whether the firmware in the image is compatible with the hardware in the cluster as per vSAN Hardware Compatibility List (vSAN HCL). The hardware compatibility check ensures that when vSphere Lifecycle Manager remediates the cluster and applies the image to all hosts, the firmware and drivers on the hosts are certified for use with vSAN.