Single Node vSAN - Cosmin`s Blog

Setting up a vSAN cluster on a single ESXi host without vCenter is simpler than you might think. This guide walks you through a CLI-based method to configure VMware by Broadcom’s vSAN in a standalone environment. Whether you’re testing in a lab or laying the groundwork for a larger cluster, a single node vSAN deployment offers a flexible starting point that scales as your needs grow.

What Is a Single Node vSAN?

VMware by Broadcom’s vSAN is designed for multi-host clusters managed by vCenter, typically requiring at least two hosts for production resilience. However, with CLI tools, you can establish a vSAN cluster on a single ESXi host. This setup is ideal for experimentation or initiating a cluster, providing a solid base for later expansion with vCenter and additional nodes.

Advantages of Single Node vSAN Deployment

A single node vSAN setup streamlines testing and initial configurations. Built on VMware by Broadcom’s powerful virtualization platform, it offers quick setup, supports proof-of-concept work, and ensures a smooth path to a full cluster—perfect for IT professionals planning phased vSAN implementations.

Prerequisites for Single Node vSAN Setup

Prepare these essentials before configuring your single node vSAN:

Hardware: One ESXi host with at least two disks—a cache disk (e.g., SSD) and a capacity disk (e.g., SSD or HDD). Check compatibility on VMware by Broadcom’s vSAN HCL.
ESXi Version: 7.0 Update 3 or later for robust vSAN support.
Access: SSH enabled on the ESXi host for CLI operations.
Networking: A VMkernel interface designated for vSAN traffic.
License: An ESXi evaluation license for testing; a vSAN license is needed with vCenter.
Time Estimate: 45–75 minutes, depending on CLI expertise.

Step 1: Check Hardware for Single Node vSAN

Confirm your ESXi host meets single node vSAN requirements.

Log into the ESXi web UI at https://<ESXi_IP>/ui.
Go to Storage > Devices to examine disks and controllers.
Validate compatibility using VMware by Broadcom’s vSAN HCL.
Ensure one cache disk and one capacity disk are available.

Note: HCL-compliant hardware enhances your single node vSAN reliability.

Step 2: Set Up Networking for Single Node vSAN Traffic

Establish a VMkernel interface for vSAN communication.

Access the ESXi web UI.
Navigate to Networking > VMkernel NICs and select Add VMkernel NIC.
Configure it:

Port Group: Choose or create one (e.g., “vSAN-Traffic”).
IP Settings: Assign a static IP (e.g., 192.168.1.10) within your subnet.
Services: Enable vSAN to tag the interface.

Save and confirm the VMkernel NIC (e.g., vmk1) is operational.

Step 3: Enable SSH for Single Node vSAN Management

Activate CLI access to manage your single node vSAN.

In the ESXi web UI, go to Manage > Services.
Find TSM-SSH, select it, and click Start.
Connect via an SSH client (e.g., PuTTY) using the ESXi IP and root credentials.

Step 4: Build the Single Node vSAN Cluster

Create the vSAN cluster on your ESXi host via CLI.

In the SSH session, execute:

 esxcli vsan cluster new

This establishes a vSAN cluster with the host as the sole member, assigning a sub-cluster UUID.

Verify the setup:

 esxcli vsan cluster get

Check for “Enabled: true” and details like Local Node UUID and Sub- Cluster UUID.

Step 5: Assign Disks to Your vSAN Cluster

Add disks to create a vSAN disk group.

List available disks:

 esxcli storage core device list

Identify cache and capacity disk IDs (e.g., naa.xxx).

Confirm disks are unclaimed:

Ensure no existing datastores use them.

Add disks to vSAN (replace placeholders with your disk IDs):

 esxcli vsan storage add -s <cache-disk> -d <capacity-disk>

Example: esxcli vsan storage add -s naa.5000cca01abc1234 -d naa.5000cca01def5678.

Validate the disk group:

 esxcli vsan storage list

Ensure disks are claimed and grouped under vSAN.

Step 6: Validate Your Single Node vSAN Deployment

Test the vSAN cluster to confirm it’s running correctly.

Check cluster status:

 esxcli vsan cluster get

Verify “Enabled: true” and a healthy host state.

In the ESXi web UI, check Storage for the “vsanDatastore”.
Deploy a test VM:

Create a small VM in the UI, selecting “vsanDatastore”.
Power it on and confirm it operates as expected.

Step 7: Prepare for v SAN Cluster Expansion

Plan to scale your single node vSAN configuration.

Record Key Info: Document the VMkernel IP, disk IDs, and Sub-Cluster UUID (from esxcli vsan cluster get).
Scaling Steps: To expand:

Deploy vCenter and integrate this host into a vSAN cluster.
Add more ESXi hosts using esxcli vsan cluster join -u <sub-cluster-uuid>.
Incorporate additional disks to expand the vSAN datastore.
Apply storage policies (e.g., FTT=1) for redundancy.

Licensing: Obtain a VMware by Broadcom vSAN license for full features.

Tip: Your single node vSAN can evolve into a multi-node cluster with ease.

Conclusion

A single node vSAN on an ESXi host without vCenter provides a versatile option for lab testing or starting a cluster build. It’s a scalable foundation that adapts as you add nodes and vCenter management. For production use, VMware by Broadcom advises a minimum of two hosts with vCenter for full resilience and functionality.