In vSAN clusters with configured fault domains, vSphere Lifecycle Manager remediates the hosts in an order that vSphere Lifecycle Manager calculates by factoring in the defined fault domains.
What Is a Fault Domain?
A fault domain consists of one or more vSAN hosts grouped according to their physical location in the data center. When configured, fault domains enable vSAN to tolerate failures of entire physical racks as well as failures of a single host, capacity device, network link, or a network switch dedicated to a fault domain. You can configure fault domains for non-stretched and stretched vSAN clusters. For more information about configuring fault domains, see the Administering VMware vSAN documentation.
Upgrading vSAN Clusters Configured with Multiple Fault Domains
vSphere Lifecycle Manager remediates vSAN clusters with configured fault domains by remediating all hosts in one fault domain at a time. To define the order of fault domains, vSphere Lifecycle Manager calculates and assigns priority to each fault domain for the vSAN cluster.
Remediation starts with the fault domain that has the highest priority. The priority of a fault domain is determined by the number of non-compliant hosts in that fault domain. The fewer non-compliant hosts in a fault domain, the higher the priority of that fault domain. However, if multiple fault domains have the same priority, vSphere Lifecycle Manager selects the first fault domain from the list of fault domains.
After vSphere Lifecycle Manager selects a fault domain, vSphere Lifecycle Manager uses DRS recommendations to select the optimal host within that domain to be remediated.
For fault domain-aware remediation of vSAN clusters, the following requirements exist:
- vCenter Server must be version 7.0 Update 1 and later
- The ESXi hosts must be version 7.0 and later
Upgrading vSAN Clusters Enabled with VMware NSX-T Data Center™ or vSphere with Tanzu
You can remediate a vSAN cluster against a vSphere Lifecycle Manager image that contains the same ESXi version as the ESXi version currently on the hosts, but the latest versions of VMware NSX-T Data Center™ and vSphere with Tanzu components. In that case, vSphere Lifecycle Manager upgrades only those components, without upgrading the ESXi version. Even in those cases, vSphere Lifecycle Manager still recognizes the configured fault domains for the vSAN cluster and performs the solution upgrade in accordance with the fault domain configuration.
- vCenter Server must be version 7.0 Update 2
- The ESXi hosts version 7.0 and later