The attached screenshot provides an introduction to virtual machines (VMs) and the concept of virtualization within the context of cloud computing, specifically focusing on how a VM operates on a physical computer.
Key Concepts:
- Virtual Machine (VM):
- A VM is defined as a software-based computer. It mimics the behavior of a physical computer but runs entirely as software within a host system.
- The virtual machine runs its own operating system (OS), which is isolated from the physical hardware but interacts with it through an intermediary layer.
- Host and Hypervisor:
- The host is the physical computer on which the virtual machines run.
- A hypervisor is the software layer that mediates access between the VMs and the physical resources of the host (such as CPU, memory, disk, and network). The hypervisor ensures that multiple VMs can run simultaneously on the same host while providing each one with the required resources.
- Type 1 Hypervisor: Directly interacts with the hardware (e.g., VMware ESXi, Xen).
- Type 2 Hypervisor: Runs on top of an existing OS (e.g., VirtualBox, VMware Workstation).
- Multiple VMs:
- The diagram illustrates two VMs: VM1 (Linux) and VM2 (Windows), showing that different operating systems can run simultaneously on the same physical machine.
- The hypervisor allows these multiple VMs to coexist without interfering with each other, leveraging the resources of the host.
- Virtualization:
- Virtualization enables the creation of multiple VMs on a single physical host. This is a key feature in cloud computing environments, where resources must be efficiently managed and shared across various workloads.
- It provides isolation between VMs, meaning issues in one VM (such as a system crash) do not affect others.
Benefits of Virtualization:
- Resource Optimization: Virtualization allows better utilization of hardware resources by running several VMs on a single physical machine.
- Cost Efficiency: Running multiple virtual machines reduces the need for multiple physical computers, lowering operational and hardware costs.
- Flexibility: Different operating systems and environments can coexist on the same hardware, enabling more flexible computing environments.
- Scalability: VMs can be provisioned, decommissioned, or migrated between hosts easily, providing scalability for dynamic workloads.