how to configure VMware HA cluster

Configuring a VMware ESXi Cluster

Prepare the Hardware: Set up the physical servers that will host the ESXi cluster. Ensure that the hardware meets the minimum requirements for running VMware ESXi. Install and configure the necessary network infrastructure, such as switches and storage devices. Configure shared storage, such as a Storage Area Network (SAN) or Network Attached Storage (NAS), that will be used by the ESXi cluster. Configure appropriate storage protocols, such as i SCSI or NSF, depending on the storage solution. Create data stores on the shared storage and ensure they are accessible by all Es Xi hosts in the cluster. Configure cluster:Enable and configure v Sphere Distributed Power Management (DPM) to optimize power usage by consolidating virtual machines on fewer hosts during low utilization periods. Configure v Sphere Update Manager (VUM) for patch management and software updates. Set up v Sphere HA Admission Control policies to define resource reservation and ensure sufficient resources are available for failover.

VMware Cluster Requirements

To create a VMware cluster, you need to ensure that your environment meets the necessary requirements. Here are the key requirements for setting up a VMware cluster:

Hardware Compatibility

  • Verify that your server hardware is compatible with the version of vMwareESXi you plan to use. Check the VMware Hardware Compatibility List (HCL) for supported servers, storage devices, and network adapters.
  • Networking Requirements:
  • Each host in the cluster must have at least two network interfaces for redundancy and to support management and virtual machine traffic separately.
  • Configure proper networking, including IP addressing, DNS, and VLAN settings, to ensure connectivity between hosts and virtual machines.
  • Shared Storage:
  • Shared storage is essential for high availability and features like v Motion and Distributed Resource Scheduler (DRS).
  • You can use Storage Area Network (SAN) technologies such as Fiber Channel (FC), i SCSI, or Network-Attached Storage (NAS) protocols like NFS.
  • Verify that your shared storage solution is compatible with VMware and supported by the ESXi version you are using.
  • v Center Server:
  • A VMware cluster requires v Center Server for centralized management and advanced features like High Availability (HA), v Motion, and DRS.
  • Install and configure vCenter Server, ensuring it meets the minimum system requirements specified by VMware.
  • DNS and Time Synchronization:
  • Ensure that DNS is properly configured to resolve host names and IP addresses.
  • Time synchronization is crucial for VMware features to function correctly. Configure NTP (Network Time Protocol) to synchronize time across all hosts and v Center Server.
  • Compute Resources:
  • Ensure that each host in the cluster meets the minimum hardware requirements for ESXi installation, including CPU, memory, and storage.
  • Consider the expected workload and ensure that the cluster has sufficient compute resources to handle the virtual machines and services you plan to run.

1. Creating a Data center for VMware ESXi Cluster

Let’s take a look at the steps to create a cluster once we have connected to the Web UI of our v Center Server in VMware v Sphere Client.

  • Right-click on your v Center Server in the Web UI and choose New Data center. The Data center object contains all the different types of objects needed to do work in the virtual infrastructure: hosts, V Ms, networks, data stores, etc.
v sphere client
  1. Next, we assign a data center name, for example, Datacenter1. Click OK to save settings.
vm new data center

3.Adding ESXi Hosts to the Datacenter

  • There are 2 ways to configure the v Center inventory and then create an ESXi cluster:
  • You add ESXi hosts to the data center, then create a new cluster and add those hosts to the cluster. This approach is used in our example.
  • You create a new cluster in the existing data center and then add data center hosts to that cluster.
  • Go to the v Sphere Client and right-click the data center there. Then, in the context menu that appears, hit
  • Add Host.

Here, you see the Add Host wizard with 7 steps to go through.

  1. Name and location. Enter the IP address of an ESXi host you want to add to the selected data center. Click Next at each step to continue.
vmware add host

4. Connection settings. Enter the administrative credentials of the ESXi host you’re adding.

Host summary. The Host summary screen shows us any V Ms that are present on the host, if any. You can also see other information about the ESXi host.

v center

5. Adding ESXi Hosts to the Data center: Add Host Wizard – Assign License

Assign license. You can choose the license that you need to use on the added host. The evaluation license is the trial license that is valid for 60 days.

Remember that Free Es Xi versions have limitations preventing you from building ESXi clusters with them.


6. Adding ESXi Hosts to the Data center: Add Host Wizard – Lock down Mode


VM location. Select the VM location. As we have one data center, this data center is selected by default.

Ready to complete. Here, the host can be added to the data center.

Every host you need to add to the v Sphere cluster should pass through this procedure. Hit Finish.

You can see two ESXi hosts added to the data center in the VMware v Center inventory in the screenshot below.

v sphere client
7.How to Create a New ESXi Cluster

After the data center creation is finished and the hosts are added, creating a new v Sphere cluster is possible.

1) Right-click the data center and hit New Cluster.

 v sphere client

We assign a cluster name, for example, Cluster1. Click OK. Later you can edit the cluster options that you can see on this screen.

v center new  cluster

Once the cluster object is added, we can add ESXi hosts to the cluster object. Right-click the cluster name in VMware v Sphere Client and click Add Hosts in the menu that opens. Once we add a host to the cluster, the host’s resources become part of the cluster resources. The cluster manages the resources of all hosts.


The Add Host wizard opens. Here, you need to provide the IP address or name of the host you want to add to the cluster.

Also, enter the required host’s access credentials.


You may receive a certificate alert. Simply click Yes to continue connecting. This is a common warning with self-signed certificates present on the hosts by default. We can safely ignore this warning.

vmware securityalert

Review your settings at the Ready to complete step and click Finish to add the ESXi host to your ESXi cluster.

vm ware

As you can now see, we have a data center and cluster, and our two ESXi hosts joined to the v Sphere cluster.

vspherer Clint interface

HA (High Availability) and DRS (Distributed Resource Scheduler) can enhance the VMware v Sphere cluster’s tolerance by reducing the probability of errors and enabling the efficient resource distribution between the VMware ESXi hosts. HA and DRS technologies and functions are unavailable when you have a standalone VMware ESXi configuration.

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