What are Virtual Machines (VMs)? Use Cases and Key Benefits

What is a Virtual Machine (VM)?

A virtual machine (VM) is a software emulation that splits a single physical computing device into many isolated computing environments, each with its allocated CPU, memory, storage, and operating system. This methodology enables maximum resource optimization while providing full isolation and independence for each computing environment. VMs are one of the precursors for modern technologies like cloud and containers.

This article will explore VMs, their common use cases, and the significant security concerns that VMs introduce. We’ll discuss leading industry tools that help safeguard your VMs from malicious activity.

VM architecture and components

Physical computers comprise several hardware components, including CPU, memory, and disk storage. VMs don't have physical hardware; they are virtualized versions of these components. Physical machines typically have an underlying operating system that communicates directly with the hardware. This is known as the host OS in VM terminology. 

To create VMs from a single physical device, the hypervisor must request resources (such as CPU, memory, storage, and network interfaces) from the host OS to build the virtual hardware. Once successfully resourced, it creates a guest OS to communicate with the newly created virtual hardware. Ideally, the host OS should minimize resource consumption, as all guest operating systems will run on top of it. 

Alternatively, some hypervisors can run directly on hardware, removing the need for a host OS entirely. This approach leads to faster resource provisioning and better resource optimization. This has become common in enterprise environments, such as cloud computing platforms.

Common use cases for VMs

The flexibility and practicality of VMs led to their wide adoption in the tech industry. Organizations of all sizes, along with independent developers and hobbyists, utilize VMs for a range of valuable use cases.

Development and testing

Software testing ensures an application behaves as expected on all platforms and operating systems. Developers use VMs to access these various environments for testing purposes. VMs also create fully isolated environments for experimentation, as you can deploy various code updates without affecting the production environment.

Server consolidation

Running a single server application on a single physical computer is often a waste of resources, because hardware components such as memory and CPU are only partially utilized by the single application. Running VM applications helps with optimizing resource utilization, especially if containers run on top of each VM.

Disaster recovery

VMs are a convenient solution for backup and recovery as they are easily replicated, provisioned, and restored. Their portability allows for quick migration to various hosts, guaranteeing business continuity with minimal downtime during outages or security breaches.

Cloud computing

Cloud environments are incredibly dynamic. Clients are continually provisioning and decommissioning compute instances with a wide variety of resource configurations. Without VMs, the flexibility and elasticity of the cloud wouldn’t be nearly as seamless as it is today.

Key benefits of using VMs

Resource optimization

The resources of a single physical computer are often more than sufficient for running the task that is delegated to that computer. This is why the concept of virtual machines is attractive, especially with the rise of cloud computing. With one physical host running multiple VMs, organizations can maximize hardware utilization while simultaneously reducing resource consumption.

Isolation and security

Apart from allocating hardware resources, the hypervisor ensures full isolation and optimal security for all running VMs. The hypervisor enforces policies that mandate the degree to which VMs can interact with one another (if at all). The hypervisor’s role as a proxy between the physical and virtual environment guarantees that the guest OS has no knowledge or method of interacting with the host OS or underlying hardware. Even if the guest OS suffers a breach, the host OS, physical hardware, and other running VMs will remain unaffected. 

Scalability and flexibility

VMs can easily and quickly be provisioned and decommissioned. This is ideal for systems running dynamic workloads, such as cloud providers. Consequently, VMs have become one of the most foundational pillars of cloud computing infrastructure and the backbone behind seamless scaling as the defining trademark of the cloud.

Cost efficiency

Most organizations are looking for opportunities to reduce waste and idle capacity while also reducing energy and hardware maintenance time. All of this can lead to significant cost savings.

Decades ago, before VMs came on the scene, hardware costs were significantly higher. The hardware ordering and delivery process was lengthy, and businesses were negatively impacted by the inability to adapt to changing demands and traffic patterns. This delay hindered growth and reduced the overall competitiveness of the business. 

Now, with VMs, organizations have a secure and fast way to get the computing power they need, while optimizing their resource usage.

Security considerations

VMs are now ubiquitous, which means they are also prime targets for cyberattacks. Some of the most common VM security threats include:

• VM sprawl: Uncontrolled VM growth is caused by misconfigured VM provisioning and decommissioning, possibly leading to unmonitored and unsecured instances that are vulnerable to attack.
• VM escape (jailbreaking): A security breach occurs when a malicious actor exploits vulnerabilities to break out of a VM and access the host system or other VMs, thus compromising overall security. Poor implementations of access control, isolation, or authorization often cause this.
• Snapshot and backup vulnerabilities: Insecure handling of VM snapshots and backups leads to sensitive data exposure or unauthorized recovery of compromised VMs.
• Poor hypervisor configuration: Misconfigurations or inadequate security settings in the hypervisor lead to poor access control and network segmentation. Improper monitoring and logging also lead to massive security breaches.

Several best practices serve as guidelines for achieving optimal VM security, which include:

• Regularly patching the hypervisor software and all software running inside the VM.
• Encrypting sensitive workloads that are running inside your VMs.
• Properly configure access control to limit VM access to operators who need it.

Finally, consider regulatory compliance when dealing with VMs. Organizations utilizing virtualization must ensure that each provisioned VM and its software meet industry compliance requirements — including adherence to relevant data protection laws, security protocols, and audit requirements to minimize the potential for regulatory violations.

Safeguard your VMs with CrowdStrike Falcon Cloud Security

Virtual machines deliver crucial value to organizations while reducing operational expenses. Developers have worked with virtualization technology for several decades, especially in recent years with the rise of cloud computing. However, virtual machines are vulnerable to security flaws, such as serious incursions or regulatory compliance breaches. 

Safeguarding VMs from threats is a must-have. And it’s most effectively accomplished by leveraging top-tier security solutions like CrowdStrike Falcon® Cloud Security. This advanced tool provides robust features, including runtime protection, streamlined management, and comprehensive visibility, ensuring optimal security for virtual environments.

Explore the CrowdStrike Falcon Cloud Security interactive demo.