VMware vSphere¶
VMware vSphere is the virtualization platform on which the entire TUKE Cloud runs. All virtual machines (VMs) that users create via the Cloud portal are launched directly on VMware infrastructure. This consists of two main technologies – VMware ESXi and VMware vCenter, complemented by VMware vRealize Automation, which provides automation and a user interface for students and teachers. Only cloud infrastructure administrators have access to these systems; users work only with the Cloud portal that runs on top of them.
VMware ESXi is a hypervisor installed directly on TUKE's physical servers. It enables running virtual machines, allocating CPU performance, RAM, disk space, and network resources. Thanks to high stability and minimal overhead, one ESXi server can run dozens to hundreds of VMs simultaneously. ESXi supports features like high availability, VM migration between servers without downtime (vMotion), snapshots, and efficient hardware management.
VMware vCenter Server is the central platform that manages all ESXi servers at once. It allows administrators to monitor performance, allocate resources, perform server maintenance, deploy updates, create clusters, distribute load, and move VMs between physical hosts. VCenter manages the entire environment so that all VMs function reliably and efficiently.
VMware vRealize Automation (vRA / vRAA) is a layer that enables automated creation and management of VMs for users without administrator intervention. vRA provides the Cloud portal where students and teachers request new VMs, extend their validity, start and stop them. It automates processes:
- VM creation on ESXi hosts,
- IP address assignment,
- operating system deployment from prepared templates,
- parameter configuration,
- sending expiration notifications,
- decommissioning unused VMs.
vRA thus replaces manual administrator work and allows users to have VMs available within minutes after approval.
Difference Between Physical Server, VM, and Container¶
Although they may seem similar, a physical server, virtual machine, and container are three distinct technologies with different characteristics.
Physical server is real hardware – processor, memory, disks, network cards. The operating system and applications run directly on it. Advantages are high performance and full control over hardware; the disadvantage is low flexibility and poor scalability. One error or overload can affect the entire system.
Virtual machine (VM) is a software emulation of a standalone computer running above a hypervisor (vSphere ESXi). A VM has its own operating system, own drivers, own disks, and network. The advantage is high isolation, stability, flexibility, and the ability to run multiple VMs on one physical server. VMs are ideal for teaching, servers, desktop environments, research, databases, or long-term processes. The disadvantage is higher resource consumption compared to containers.
Container (e.g., Docker) is an even lighter form of virtualization. Unlike a VM, it does not include an entire operating system but shares the host system's kernel. A container contains only the application and its dependencies. Thanks to this, it's extremely fast, lightweight, and instantly launchable. It's ideal for modern applications, microservices, development, DevOps, testing, or programming education. The disadvantage is lower isolation compared to VMs and less suitability for full desktop systems.
Brief comparison:
| Technology | Description | Speed | Isolation | Suitable For |
|---|---|---|---|---|
| Physical server | Real hardware | N/A | maximum | HPC, large databases, special HW |
| VM (vSphere) | Virtual PC with own OS | seconds | very high | teaching, servers, projects, research |
| Container (Docker) | Lightweight isolated environment | milliseconds | medium | applications, DevOps, microservices |
Physical server → VM → Container represents the natural evolution toward higher efficiency and scalability.