The main benefit of using a cluster in vCenter is the ability to manage and balance resources across multiple physical servers. Clustering allows for increased scalability and availability, as well as improved performance and resource utilization.
When a cluster is created in vCenter, multiple physical servers (known as hosts) are grouped together as a single entity. This allows for centralized management of virtual machines (VMs) and resources such as CPU, memory, and storage. vCenter uses a variety of features such as vSphere High Availability (HA) and Distributed Resource Scheduler (DRS) to automatically distribute and balance workloads across the hosts in the cluster. This helps to ensure that VMs have access to the resources they need to operate efficiently, while also providing redundancy and failover capabilities in the event of a host failure.
In technical terms, vCenter uses a shared storage system such as a SAN or NAS to allow VMs to be moved between hosts within the cluster without requiring downtime. This process, known as vMotion, uses a combination of live migration and network virtualization to seamlessly transfer VMs between hosts. vSphere HA monitors the health of the hosts and VMs in the cluster, and can automatically restart VMs on a different host in the event of a failure. DRS uses real-time analytics and algorithms to balance workloads across hosts to ensure optimal performance and utilization of resources.
