Adding a cluster to a workload domain gives you a fresh pool of compute and storage inside a domain you already run, without standing up a new domain or a second vCenter. In VCF 9.1 you build the new cluster with the Create SDDC Cluster wizard in the vSphere Client, and the platform wires it into the domain vCenter, into NSX, and into vSphere Lifecycle Manager for you. This part walks the wizard end to end for a vSAN ESA cluster, and points out where NFS and Fibre Channel differ.

Run this only when a domain needs a separate cluster, for example to isolate a workload tier, to place a cluster on a different storage backing, or to grow past the host count you want inside one cluster. To add hosts to a cluster that already exists, follow the neighbouring part on adding ESX hosts to a cluster, which also documents host commissioning in full. For the wider operating model and where each console fits, see the Day-2 operations overview, and for how the domain itself was built, see the VCF 9.1 Deployment guide.

Prerequisites

Work through each row below before you open the wizard. Most cluster build failures trace back to a missed prerequisite, usually a host commissioned for the wrong storage type, an exhausted overlay pool, or a network pool that does not match the storage you chose.

Step 1, Plan the cluster and confirm the domain

Start by confirming the domain is healthy and by fixing the shape of the new cluster: storage type, host count, and switch layout. A vSAN ESA HCI cluster needs at least three hosts, and your Failures to Tolerate choice raises that minimum.

1. In VCF Operations, open the target workload domain and confirm it reports a healthy state with no open critical alerts.
2. In the vSphere Client, browse to the VCF instance datacenter for the domain and note its exact name.
3. Decide the principal storage type for the new cluster, for example vSAN with ESA enabled.
4. Decide the host count from the storage type and the Failures to Tolerate value you plan to set.

Step 2, Commission hosts for the cluster storage type

Commissioning adds hosts to the shared Unassigned Hosts inventory so the wizard can pick them. Commission each host for the same storage type as the cluster, because a host commissioned for vSAN ESA can only join a vSAN ESA cluster. The neighbouring part on adding ESX hosts covers this workflow field by field, so keep it brief here.

1. In the vSphere Client, click Global Inventory Lists, then Hosts, then Unassigned Hosts.
2. Click Commission Hosts, review the Checklist page, click Select All, then click Proceed.
3. Select Add new for one host, or Import to upload a JSON file for several hosts at once.
4. Type the Host FQDN, set the Storage Type to match the cluster, and select a Network Pool Name that supports that storage.
5. Type the host root User Name and Password, click Add, activate Confirm All Finger Prints, then click Validate All.
6. Click Next, leave Skip failed hosts during commissioning enabled, then click Commission.

To commission several hosts in one pass, download the JSON template from the Import option and add one block per host. Valid storage type values are VSAN, VSAN_REMOTE, VSAN_ESA, VSAN_MAX, NFS, VMFS_FC, and VVOL.

[
  {
    "hostname": "esx09.wld01.example.local",
    "username": "root",
    "password": "REPLACE_WITH_ROOT_PASSWORD",
    "storageType": "VSAN_ESA",
    "networkPoolName": "wld01-network-pool"
  }
]

Step 3, Start the Create SDDC Cluster wizard

You build the cluster from the datacenter object in the domain vCenter. If you do not have VCF SSO with vCenter linking, run this from the management domain vCenter, or use the SDDC Manager UI as a fallback for the same task.

1. In the vSphere Client for the domain vCenter, browse to the VCF instance datacenter in the inventory.
2. Select the datacenter, then click Actions, New Cluster, Create SDDC Cluster.

Step 4, Choose the storage type and name the cluster

Storage type drives the rest of the wizard, so set it first. For vSAN you also decide here whether the cluster uses the Express Storage Architecture.

1. Select the storage type for the cluster: vSAN, NFS, VMFS on FC, or vVol.
2. For a vSAN cluster, select Enable vSAN ESA to build a vSAN ESA cluster, or leave it clear for vSAN OSA.
3. Click Begin.
4. Enter a name in the cluster Name field.
5. Select a cluster image from the image drop-down menu.
6. Click Next.

Step 5, Enter the storage details

This screen changes with the storage type you picked. For vSAN ESA you set the cluster type and availability, while the storage type and policy are fixed for you.

1. For vSAN, set the vSAN Cluster Type to vSAN HCI for storage and compute, or vSAN Storage for storage only.
2. Set Failures to Tolerate to the availability level you need, which fixes the minimum host count.
3. For a vSAN ESA HCI cluster, confirm Storage Type shows the local vSAN datastore and Storage Policy shows auto policy management, both of which are read only.
4. Click Next.

For an NFS cluster this screen asks instead for a Datastore Name, a Folder path, and the NFS Server IP Address. For a VMFS on FC cluster it asks only for a Datastore Name, and the hosts must already see the FC array. Fill the fields for your storage type, then click Next.

Step 6, Select hosts for the cluster

Pick the commissioned hosts that will form the cluster. Only hosts commissioned for the storage type you chose appear here, and the Next button stays disabled until you select enough of them.

1. On the Host Selection page, select the commissioned hosts for the cluster.
2. Set Skip failed hosts during cluster creation on to continue past an unhealthy host, or off to fail the build if any selected host is unhealthy.
3. Confirm you have selected at least the minimum host count, at which point Next becomes available.
4. Click Next.

Step 7, Choose a distributed switch profile

Each profile maps traffic types to one or more vSphere Distributed Switches. Start from the Default profile unless your design separates storage or NSX traffic onto dedicated NICs.

1. Select a switch profile: Default for a single switch, or a separation profile such as Storage Traffic Separation or NSX Traffic Separation.
2. For a bespoke layout, select Custom Switch Configuration to define one or more distributed switches by hand.
3. Assign the host physical NICs to the uplinks on each distributed switch.
4. Click Next.

Step 8, Review and finish

Review the summary, commit the build, and watch the task. You can run several create cluster tasks at the same time, so one long build does not block work on another domain.

1. On the Review page, check the cluster name, storage, hosts, and switch configuration.
2. Click Finish.
3. Open the Recent Tasks pane and watch the create cluster task run to completion.

How to verify the new cluster

Run these checks after the create cluster task reports success. Confirm the cluster is a full member of the domain, that its storage is healthy, and that it sits on the right image.

1. In the vSphere Client, confirm the new cluster appears under the datacenter with every selected host connected.
2. For a vSAN cluster, open Monitor, then vSAN, then Skyline Health, and confirm the checks pass and the datastore is present.
3. On the cluster Updates tab, confirm the cluster reports as compliant with its assigned image.
4. In VCF Operations or the SDDC Manager UI, confirm the new cluster is listed under the workload domain.
5. In NSX Manager, confirm transport nodes were created for the new hosts and show a healthy state.

Common errors and fixes

Common questions

Can each cluster in a domain use a different storage type?
Yes. A workload domain can hold clusters on different principal storage, so one cluster can run vSAN ESA while another runs NFS or VMFS on FC, as long as every host inside a single cluster uses the same type.

Do I need a new vCenter for the new cluster?
No. A new cluster joins the existing domain vCenter. You only get a new vCenter when you create a new workload domain, which is a separate task.

How many hosts does a vSAN ESA cluster need?
A vSAN ESA HCI cluster needs a minimum of three hosts, and a higher Failures to Tolerate value raises that minimum. The wizard keeps the Next button disabled until you select enough healthy hosts.

Can I build more than one cluster at a time?
Yes. Create cluster tasks can run in parallel, subject to the parallel task limits in the VMware configuration maximums tool.

References

• Broadcom TechDocs, Add an SDDC Cluster to a VCF Domain
• Broadcom TechDocs, Commission ESX Hosts
• Broadcom TechDocs, Managing VCF Domains in VMware Cloud Foundation
• Broadcom TechDocs, vSAN in VMware Cloud Foundation 9.1

About The Author

Dr. Pranay Jha

Dr. Pranay Jha is a Cloud and AI Consultant with 18+ years of experience in hybrid cloud, virtualization, and enterprise infrastructure transformation. He specializes in VMware technologies, multi-cloud strategy, and Generative AI solutions. He holds a PhD in Computer Applications with research focused on Cloud and AI, has published multiple research papers, and has been a VMware vExpert since 2016 and a VMUG Community Leader.

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