Information in the VMware Compatibility Guide and vSAN Release Catalog is combined with information about the currently installed ESXi release. The vSAN Release Catalog maintains information about available releases, preference order for releases, and critical patches needed for each release. When a new, compatible update becomes available, a notification is proactively displayed in vSAN Health. This eliminates the manual effort of researching and correlating information from various sources to determine the best release for an environment.
Administrators can use the Remediate option in vSphere Update Manager to perform a rolling upgrade of the cluster. vSphere Update Manager migrates virtual machines from the host being upgraded to other hosts in the cluster with no downtime.
Key Causes for vSAN Build Recommendation Engine Health Alert:
No/Restricted Internet Access: The vCenter server cannot reach vcsa.vmware.com or other online repositories, commonly seen in "dark sites".
Invalid or Expired Credentials: My VMware credentials are not set or have expired.
VUM/vLCM Issues: The vSphere Update Manager (VUM) or vSphere Lifecycle Manager (vLCM) service is down, inactive, or not responding.
Service Migration: Ongoing migration of VMware services to the Broadcom domain can impact connectivity.
Missing ISOs: Required ESXi ISO images have not been uploaded to the VUM server.
Outdated Metadata: The vSAN release catalog database is outdated or cannot be downloaded.