The power of computers transformed the world in the last century. Today, they serve our critical infrastructure, business operations, and more. Though tempting to think of a universe of physical machines in office buildings and server farms, virtual machines (VMs) have actually been the cornerstone of enterprise computing in the new millennium.
A VM gives administrators the power to manage hundreds of virtual computers from a single physical device. Already a popular choice for server virtualization, VM deployment is fit for hybrid infrastructures of today. Notably, virtual machines consolidate data and processes hosted physically and enable the access of other operating systems for use.
This article dives into what a virtual machine is, why it’s valuable, how it works, and what to consider when moving towards virtualization.
Also Read: Best Server Virtualization Software for 2021
What is a virtual machine?
A virtual machine is a self-contained server that doesn’t rely on hardware for operations and instead uses software. An administrator can run multiple guest virtual machines, with their OS and purpose, from a single physical host server.
As a reference, operating systems are the foundational software placed in hardware for managing the entirety of a machine’s operations. However, because applications – the software programs designed for end-users – are OS-specific, the native operating system can limit users’ ability to explore other systems and applications.
Like its host server, the virtual machine contains memory, a network interface, storage, and an allotted CPU capacity. A hypervisor separates VM guests from each other, while the physical host’s resources are shared between VMs as needed. While virtualization technology launched in the 1960s, it wasn’t until VMware’s launch of their workstation in 1999 that VMs became a marketable solution.
VM’s Hardware Imposter Syndrome
Virtual machines operate like any other computer with a fraction of the physical hardware. So, for example, an administrator could run a dozen VMs from their host computer, and each one would act as an independent operating system. And therein lies the imposter syndrome for virtual machines. While VMs can do a lot, they are naturally less productive than their standalone physical hosts.
Virtual Machines vs. Containers
Containers and virtual machines are often confused because they both run isolated applications from a single platform. Where they differ is their size, speed, workload productivity, and integration into the host machine.
While VMs can emulate a computer’s hardware and measure in gigabytes of data, containers usually only hold a single application or process held in megabytes. Because containers are lightweight, they have a natural advantage over VMs in speed and microservice deployment. Virtual machines, by comparison, are better suited for managing larger workloads and applications.
To learn more about virtual machines and containers, read our guide on Virtualization vs. Containerization.
Why do I need a virtual machine?
Have you ever wanted more than one computer? Is an old computer depreciating fast, and you want to preserve its contents? Are you developing an application for Windows, Mac, and Linux?
If these questions apply to you, a VM can be a valuable addition to your technology toolkit. From creating an army of computers to preserving older data and developing applications that work across operating systems, virtual machines do all of this and more. Another attractive feature of virtualization is how it impacts inventory and costs. With just a fraction of the hardware, including disks, drives, and server equipment, organizations can cut costs, increase utilization and reduce hardware headaches.
Also Read: VMware vSphere 7 Security & Features
Virtual machines are most relevant to data centers, software developers, and IT organizations, although they can also be used on PCs and laptops for those looking to isolate a workload or application.
Types of virtual machines
|Process Virtual Machines||System Virtual Machines|
|Alternative names||Language Virtual Machine or Managed Runtime Environment||Hardware Virtual Machine|
|Uses||Software simulation; mimicking the behavior of the device||Software emulation; duplicates exactly as it exists|
|Capabilities||Run a single program or process||Full computer OS access|
|Abstraction||Instruction set architecture (ISA)||High-level programming|
Deploying a virtual machine
Hypervisors, the Virtual Machine Managers
The technology behind virtual machine deployment is the software mechanism known as a hypervisor. Located between hardware and the guest virtual machines, a hypervisor runs on the physical host machine and supervises existing VMs. Not just for server virtualization, hypervisors are capable of virtualizing applications, storage, and desktops.
Deploying a hypervisor offers administrators the needed management capabilities as well as an opportunity to implement microsegmentation. Another development gaining speed is the sale of devices embedded with a hypervisor like the kernel-based virtual machine (KVM) for Linux. Top hypervisor vendors include VMware, Microsoft, and Red Hat.
Dive into how these software-based managers operate with our Guide to Hypervisor Servers.
Virtual machine use cases
Perhaps the greatest benefit of virtual machine adoption is the expanded capacity for storage, applications, and processing. Virtualization presents an opportunity to condense workloads and therefore reduce the physical spaces they reside in and the amount of equipment and overhead required. With a smaller on-premises footprint, organizations can manage more than ever before.
Run Legacy Software
Legacy software applications can cease to be of use or no longer available to employees of an organization. This could be due to an intentional migration by the IT team or a move to end support by the software developers. In either case, personnel’s desire to use legacy apps isn’t a dealbreaker. With VMs, the user can recreate the environment needed to operate the discontinued program.
Also Read: IBM PowerVM Features & Pricing
Utilizing Different Operating Systems
The most common use case for virtual machines is accessing a fleet of different operating systems from a single physical host. No matter the host’s native OS, IT staff’s ability to create or replicate new machines that run on other operating systems make cross-OS development a much easier task. In addition, having access to different operating systems can mean doing anything the native OS client could do for other users.
When tinkering with virtual machines, users will find the snapshot feature helpful for saving a version of their guest machine. Much like an actual photograph, this function gives clients the chance to preserve the state and data, including disks, memory, and VNI cards. Users can create and manage multiple snapshots for testing on their VM, but be aware – running a VM on a snapshot for extended periods can cause instability and data loss.
Interested in learning more about data loss, how to protect your data, and remediation? Read our Guide to Disaster Recovery.
Developing Non-Native OS Software
A consistent theme of virtual machines is their value to developers and professionals who require a lot of access to different computer systems. Whereas programmers not so long ago had to split their time between devices and types of devices (desktop vs. mobile platforms), virtual machines open the door to faster and smoother cross-OS application development.
Function as a Sandbox
One server security feature of virtual machines is that they are isolated environments within the physical hosts. Unbeknownst to themselves, they are not independent computers using their own hardware, nor are their OS and applications connected to the host or other guest machines. As a result, VMs can be an excellent location to test suspicious files, new projects, and more as an isolated setting.
Beyond VMs, advanced malware analysis is a must for SMBs to large enterprises today. Read more on how Sandboxing in 2021 works, why it’s crucial, and vendors offering solutions.
System Exploration and Tinkering
While developers might have a detailed plan of objectives when using a computer, technology enthusiasts often start using without any plan at all. With an instruction manual, web guide, or less, many users want to explore their device’s capabilities. For the curious, virtual machines offer a playground – not unlike the sandbox – for tinkering without consequences. Whether it’s learning a new OS or deconstructing a computer, VMs give interested users a space to explore.
Replicate VM to Other Machines
Considering a single host could serve multiple virtual machines, it’s easy to understand why they’re also replicable. The one caveat to this feature is that VMs are limited to destinations served by their hypervisor. Otherwise, a VM is contained in a few files and can be transferable to other hosts.
Hot off the presses, read about how ransomware groups are targeting VPNs on eSecurityPlanet.
Virtual machine considerations
- Run multiple OS on a single physical computer
- Saves space, time, and management costs
- Support for legacy applications
- Instruction set architecture (ISA)
- Less efficient than a full physical PC
- Cannot replace entire physical infrastructure
- Unstable performance if the host is under extreme stress
Virtual Machine Market
According to MarketWatch, the virtual machine market size forecast sees the industry growing at a CAGR of 2.9% to $4.32 billion in 2026, from $3.53 billion in 2019. VMware, IBM, and Huawei hold the top market positions, combining for almost three-quarters of the market share. Market vendors include:
- Red Hat
Also Read: Oracle VM Server & Software
VMs enable operational flexibility
Though computer virtualization dates back to the 1960s, the proliferation of virtual machines is a 21st-century phenomenon. As software development and applications have grown in priority, access to multiple operating systems and isolated internal environments is crucial. In all, virtual machines offer:
- Operational flexibility
- Centralized management
- Disaster recovery protection
- Reduced overhead and downtime
To service the organizations, applications, and workloads of tomorrow, VMs will continue to be a valued component of enhancing business productivity.