Introduction
In this article, we’ll dive deeper into the concept of vCenter Clusters, exploring their components, configuration options, and the advantages they bring to your virtualized environment. So, let’s get started and unlock the full potential of vCenter Clusters!.
A cluster comprises of ESXi hosts. When a host is added to a cluster, its resources become part of the Cluster resource pool. Consequently, as more hosts are incorporated into the cluster, additional resources become available. In vSphere 6.7 onwards, it is possible to establish and configure a hyper-converged cluster where storage, networking, and compute all operate within a single software layer on industry-standard x86 servers. Creating clusters is necessary to enable vSphere High Availability, vSphere Distributed Resource Scheduler, and VMware vSAN. In vSphere 7.0, it is now possible to use a single image for cluster creation, as well as conveniently update and upgrade the software on the hosts within the cluster using images from vSphere Lifecycle Manager. Furthermore, starting with vSphere 7.0 Update 2, you can select a reference host during cluster creation and utilize its image for the newly formed Cluster.
When you create a Cluster, you can enable the following:
• vSphere Distributed Resource Scheduler (DRS)
• vSphere High Availability (HA)
• Virtual Storage Area Network (vSAN)
You also have the capability to oversee all hosts within the cluster using a solitary image. This choice permits you to designate a single image to each host in the cluster, thus eliminating any disparities between them. Additionally, it offers additional functionalities such as hardware compatibility verification, cluster-wide remediation, and simplified upgrades. To utilize this feature, the hosts must be operating on ESXi 7.0 or a more recent version, and it will replace the existing baselines. Once enabled, baselines cannot be utilized in this particular cluster.
Create a Cluster
To accomplish this task in the vSphere Client, simply perform the following steps: right-click on the Datacenter name, choose the option New Cluster from the context menu, and assign a name to your newly created Cluster, as depicted in Figure below.
If you decide not to provide a custom name, vCenter will automatically assign the default name New Cluster. Proceed by clicking on Next and then Finish to complete the process.
With your first vCenter Cluster in place, the next task is time to add your ESXi host to the Cluster. You can create some extra ESXi hosts (at least one more).
Add Your ESXi Host to vCenter
To incorporate your ESXi host into vCenter, simply right-click on the Cluster name in the vSphere Client and choose the “Add Hosts” option from the context menu. In the Add hosts pop-up wizard, include the ESXi host that you had created earlier (with its name, root username, and password). If the username and password are identical for all ESXi hosts, you can select the “Use the same credentials for all hosts” checkbox, eliminating the need to add them individually. Proceed by clicking “Next.”
In the second step of the Add hosts wizard, take a look at the summary of the ESXi host and see if there are any warnings. Figure 10-5 displays a warning, which indicates that there is already one virtual machine running on one of the ESXi hosts. Generally, this is not an issue, but rather an informational message about the ESXi host being added to the vCenter. In this case, it refers to the vCenter created in the previous chapter. Proceed by clicking Next.
In the final wizard step, shown in Figure, double-check the ESXi host information. If all is okay, click Finish to add the ESXi hosts to your
Cluster.
If there is no problem with the IP/FQDN or the network of your ESXi hosts, vCenter starts to import them to the Cluster.
Now you have created your vCenter Cluster. As shown in Figure below, one of the hosts in this demonstration has a yellow warning icon.
Select the ESXi host, and the Summary tab displays the warning messages, as shown in Figure below. The warnings are about the console
ESXi Shell and SSH being enabled for this host.
Conclusion
In this Blog post we learned about vCenter cluster. We then setup and configure the Cluster in vCenter and add ESXi host in this Cluster. By grouping these resources together into a cluster, vSphere provides enhanced capabilities and benefits, such as workload balancing, high availability, and increased scalability. When a host fails or undergoes maintenance, the VMs can be automatically migrated to other hosts within the cluster, ensuring continuous application availability.
