You can add clusters to a cloud SDDC up to the maximum configured for your account.

Additional clusters are created in the same availability zones as the initial SDDC cluster. All hosts in a cluster must be of the same type, but they don't have to be the type used in the cluster initially created for the SDDC (Cluster-1). Logical networks you have created for your SDDC are automatically shared across all clusters. Compute and storage resources are configured similarly for all clusters. For example:
  • Each cluster contains a Compute-ResourcePool that has the same permissions as the one created in the initial SDDC cluster.
  • Each cluster contains a workloadDatastore that has the same permissions as the one created in the initial SDDC cluster.
  • The initial cluster (Cluster-1) contains the Mgmt-ResourcePool and vsanDatastore. All management appliances run in this cluster. All clusters contain a workloadDatastore and can run virtual machine workloads.

When you deploy a new SDDC, all host CPUs in the initial SDDC cluster (Cluster-1, which supports SDDC management appliances) are enabled. You cannot deactivate any host CPUs in Cluster-1. However, if you deploy additional clusters, you can choose to deactivate some of the host CPUs in those clusters, which can help save on licensing costs for software that is licensed on a per-CPU basis. Custom core counts can be selected only during cluster creation and only for secondary clusters. Custom core counts are not supported in Cluster-1 because all cores are required for management VMs. For configuration and capacity details covering conventional two-host clusters and stretched four-host clusters, see the VMware TechZone article Entry-level Clusters on VMware Cloud on AWS

Procedure

  1. Log in to the VMware Cloud Console at https://vmc.vmware.com.
  2. Click Inventory > SDDCs, then pick an SDDC card and click VIEW DETAILS.
  3. On the card for the SDDC you want to add a cluster to, select Actions > Add Cluster.
  4. Select the host type.

    For more information, see VMC on AWS Host Types.

  5. Specify the number of CPU cores to enable for each host in the cluster.
    Two-host clusters require you to enable at least 8 CPUs. .
    For i3 hosts, all CPU cores are enabled by default on each host in the cluster. If you'd like to disable some of the cores to save on licensing costs for applications that are licensed on a per-core basis, you can enable a subset of the available cores. This subset applies to all hosts in the cluster. Other cores on each host are disabled and remain disabled for the lifetime of the host.

    For i3en hosts, all CPU cores are hyperthreaded and offered as logical cores by default on each host in the cluster. If you'd like to disable some of the cores to save on licensing costs for applications that are licensed on a per-core basis, you can enable a subset of the available cores. This subset is offered as physical cores and applies to all hosts in the cluster. Other cores on each host are disabled and remain disabled for the lifetime of the host.

    Important: Reducing core count affects the compute performance of all workloads on the host and increases the likelihood of system performance degradation. For example, vCenter and vSAN overhead can become more noticeable, and operations like adding clusters and hosts can take longer to complete.
  6. Select the number of hosts in the cluster, and Click Add Cluster.

Results

A progress bar shows the progress of cluster creation.