What Are Virtual Machines & How Do They Work?
For a business to thrive and grow, it’s vital to adopt innovations that make operations and other business processes more efficient. Doing this right means investing in tech solutions that can run seamlessly with your existing or planned IT infrastructure. Virtual machines are useful tools that you can consider to enhance the tech performance of your business.
What are virtual machines?
Virtual machines or VMs are digital iterations of physical computers which are primarily used to run different operating systems (OS) on a single device simultaneously. They let the underlying hardware handle the operating systems and their installed applications in an interoperable manner.
The concept was introduced in the 1960s by computer experts at IBM. Their creation – the VM/370 – is considered one of the earliest implementations of virtual machines. It was designed to run multiple instances of IBM’s time-sharing operating system called CP/CMS (Control Program/Cambridge Monitor System) on IBM mainframe systems.
Since then, VM technology has evolved significantly, and it is now widely used across various platforms. Different virtualization technologies and products have emerged, such as VMware, Microsoft Hyper-V, and open-source solutions like KVM and Xen, providing virtualization capabilities to a wide range of users and organizations.
How do virtual machines work?
Guest operating systems can run on virtual machines, which can be different from the host operating system. This is possible due to the deployment of a hypervisor or virtualization layer. It is a software layer that sits between the hardware and the guest OS. There are two types of hypervisors: Type 1 or bare-metal, and Type 2 or hosted.
Type 1 Hypervisor
This type runs directly on the physical hardware and manages the guest OS. It provides better performance and is commonly used in enterprise environments.
Type 2 Hypervisor
A hosted hypervisor runs an application on an existing operating system and manages the guest operating systems. It is often used for personal or development purposes.
The hypervisor then creates virtual machines by allocating resources from the physical hardware and presenting them to each VM as virtual resources. These resources include CPU, memory, disk space, network interfaces, etc.
How does the actual hardware handle VM instances?
A computer is able to handle VM instances because the hypervisor creates a virtualized set of hardware components for each virtual machine. These virtual hardware components include CPUs, memory, and network interfaces. The hypervisor manages the allocation and scheduling of these resources among the virtual machines.
The hypervisor also allocates physical resources to the virtual machines based on their needs and priority. It ensures that each VM gets its fair share of resources and prevents one VM from impacting the performance of others. If more powerful VMs and more instances are needed, you can procure additional assets like enhanced servers and extra storage capacity.
How can multiple virtual machines run smoothly in one machine?
The hypervisor is developed to deploy various strategies to allow the smooth performance of multiple VMs. First, it provides isolation between different virtual machines. If one VM crashes or is compromised, it doesn’t affect other VMs or the host system. Security features like secure boot, virtual firewalls, and access controls can be implemented within each VM.
It can also implement time slicing or multi-threading to share the physical CPU among the VMs. It allocates CPU cycles to each VM for a specific duration and switches to another instance, giving the illusion of simultaneous execution. This process is called a context switch. The context of the current VM is saved, including the state of registers, memory, and other resources, and the context of the next VM is loaded.
VMs also have snapshot support, which allows capturing the entire state of an instance at a specific point in time. This feature enables easy backup, restoration, and cloning of VMs. VMs may be migrated from one physical machine to another without disrupting their operation.
Conclusion
VMs enable efficient resource utilization, easier data management, and flexibility in running multiple OS and applications. Be sure to combine the use of this technology with other strategies and best practices on network maintenance, security, and personnel training. Doing so lets you maximize their capabilities, elevating your business one step toward success.
