Tenant workloads run on the ESXi hosts in the shared edge and compute cluster. Because ofthe shared nature of the cluster, NSX-T Edge virtual machines also run in this cluster. The design decisions determine the number of ESXi hosts and vSphere HA settings and several other characteristics of the shared edge and compute cluster.

Table 1. Shared Edge and Compute Cluster Design Decisions

Decision ID

Design Decision

Design Justification

Design Implication

NSXT-VI-VC-003

Create a shared edge and compute cluster that contains tenant workloads and NSX-T Edge virtual machines.

Limits the footprint of the design by saving the use of a dedicated vSphere edge cluster.

In a shared cluster, the VLANs and subnets between the VMkernel ports for ESXi host overlay and the overlay ports of the Edge virtual machines must be separate.

NSXT-VI-VC-004

Configure Admission Control for one ESXi host failure and percentage-based failover capacity.

vSphere HA protects the tenant workloads and NSX-T Edge virtual machines in the event of an ESXi host failure. vSphere HA powers on virtual machines from the failed ESXi hosts on any remaining ESXi hosts.

Only a single ESXi host failure is tolerated before potential resource contention.

NSXT-VI-VC-005

Create a shared edge and compute cluster with a minimum of four ESXi hosts.

Allocating four ESXi hosts provides full redundancy within the cluster.

Four ESXi hosts is the smallest starting point for the shared edge and compute cluster for redundancy and performance thus increasing cost.

NSXT-VI-VC-006

Create a resource pool for the two large sized edge virtual machines with a CPU share level of High, a memory share of normal, and a 32-GB memory reservation.

The NSX-T Edge virtual machines control all network traffic in and out of the SDDC. In a contention situation,these virtual machines must receive all the resources required.

During contention NSX-T components receive more resources than all other workloads.As a result, monitoring and capacity management must be a proactive activity.

NSXT-VI-VC-007

Create a resource pool for all user virtual machines with a CPU share value of Normal and a memory share value of Normal.

Creating virtual machines outside of a resource pool would have a negative impact on all other virtual machines during contention. In a shared edge and compute cluster, the SDDC edge virtual machines must be guaranteed resources above all other workloads as to not impact network connectivity. Setting the share values to normal gives the SDDC edges more shares of resources during contention ensuring network traffic is not impacted.

During contention,tenantvirtual machines might be starved for resources and experience poor performance. Proactively perform monitoring and capacity management, add capacity or dedicate an edge cluster before contention occurs.

NSXT-VI-VC-008

Create a host profile for the shared edge and compute cluster.

Using host profiles simplifies configuration of ESXi hosts and ensures settings are uniform across the cluster.

After you add the ESXi hosts as Transport Nodes, the host profile are no longer usable and must be removed from the cluster.

The host profile is only useful for initial cluster deployment and configuration.