Starting with vSphere 7.0, you can use vSphere vSphere Lifecycle Manager images to upgrade the firmware of the servers that run in your vSAN clusters.

In a vSAN cluster, the SCSI controller firmware and the physical drive firmware are handling most of the data communication. To ensure your vSAN cluster health, you must perform controller firmware updates, when necessary.

Because firmware updates affect the hardware layer in your vSphere environment, they usually are rare events. Firmware updates occur during initial ESXi host setup or during major updates of vSphere or vSAN.

In earlier vSphere releases, firmware updates are delivered as baselines in the vSAN-managed baseline group. You must use a special vendor-provided tool that vSAN uses to detect, download, and install firmware updates.

Starting with vSphere 7.0, the recommendation baseline group contains only patch updates and driver updates. It no longer contains firmware updates. As a result, you cannot use baselines to update the firmware in your vSAN clusters if the ESXi hosts are of version 7.0 or later. You can still use baselines to perform firmware updates on hosts of earlier versions, for example 6.7. But to perform firmware updates on hosts that are of version 7.0 and later and that are in a vSAN cluster, you must manage that cluster with a single image. You must also deploy an OEM-provided hardware support manager and register it as a vCenter Server extension. The hardware support manager inspects the hardware of the hosts in the cluster and lists available and compatible firmware versions, which you can add to the image for the cluster. The actual firmware update happens upon remediating the cluster against an image that contains a firmware add-on.

For more information about the requirements for using images, see System Requirements for Using vSphere Lifecycle Manager.

For more information about performing firmware updates by using images, see Firmware Updates.