Containers and virtual machines are both essential technologies for resource virtualization. According to a recent study, 72% of organizations utilize containers for their application deployment, while 58% employ virtual machines for efficient resource management and isolation.
Virtual machines offer the advantage of running multiple operating systems on a single server, while containers excel in rapid deployment and scalability within a single host operating system.
Organizations can decide which technology best suits their resource utilization and application deployment needs by understanding their distinctions.
What is a Container?
Containers are nimble software packages encompassing all the essential dependencies required to execute a particular application. These dependencies encompass a wide range of components, including system libraries, external code packages, and other applications operating at the level above the underlying operating system.
Unlike virtual machines, which virtualize entire machines, containers focus on operating at higher stack levels, offering a more streamlined and efficient approach.
All the necessary dependencies are neatly bundled within a container, creating a self-contained environment for the application to thrive.
By encapsulating these dependencies, containers ensure that the application can be seamlessly deployed and run across different computing environments, regardless of variations in underlying systems or configurations.
This eliminates concerns about missing dependencies or compatibility issues, enabling smooth and hassle-free application execution.
Agility in Iteration
Containers excel in speed when modifying and iterating software. Due to their lightweight nature and focus on high-level software, containers allow for swift and efficient updates, reducing development time and enhancing agility in the software development process.
Container runtime systems typically provide access to comprehensive repositories of pre-built containers. These repositories contain many popular software applications, such as databases and messaging systems.
Development teams can leverage these ready-to-use containers, instantly downloading and executing them, thereby saving valuable time and effort in setting up and configuring software components.
Shared Host Vulnerabilities
Containers share the underlying hardware system below the operating system layer. This shared environment introduces a potential risk wherein an exploit in one container could potentially breach the container's isolation and impact the shared hardware or other containers.
Therefore, implementing proper security measures and regularly updating containers to mitigate such risks is essential.
Security Concerns with Public Images
Popular container runtimes often provide public repositories of pre-built containers. While these repositories offer convenience, a security risk is associated with using publicly available container images.
These images may contain vulnerabilities or exploits, making them susceptible to being hijacked by malicious actors. Therefore, consideration and scrutiny of container images are necessary to ensure a secure and trusted environment.
Popular container providers
Simplifying Container Deployment Docker, the leading container runtime, revolutionized the world of containerization with its user-friendly approach. Docker Hub, a massive public repository, provides many pre-built containerized software applications.
This repository allows developers to download and deploy containers effortlessly on a local Docker runtime, streamlining the deployment process and reducing time and effort.
A Security-First Container System RKT, pronounced as "Rocket," is a container system that prioritizes security. Unlike other container runtimes, RKT restricts insecure container functionality by default unless explicitly enabled by the user.
RKT aims to provide a more robust and secure container runtime system by addressing cross-contamination and exploitative security issues.
Linux Containers (LXC)
Linux Containers (LXC) is an open-source container runtime system that isolates operating and system-level processes.
It serves as the underlying technology used by Docker. LXC offers a vendor-neutral solution, enabling containerized application development and facilitating a flexible, open-source container runtime environment.
Lightweight Container Runtime for Kubernetes CRI-O implements the Kubernetes Container Runtime Interface (CRI) that allows Open Container Initiative (OCI) compatible runtimes.
As a lightweight alternative to using Docker as Kubernetes's container runtime, CRI-O efficiently manages containerized workloads. It enables streamlined container deployment and resource utilization within Kubernetes clusters.
In virtualization, containers operate at the software layer, facilitating the concurrent execution of multiple applications on a physical server. In addition, each container operates within its isolated environment, encapsulating its dependencies and providing a lightweight footprint that optimizes resource utilization.
This differs from virtual machines that virtualize the entire hardware and operating system stack, requiring more storage space and resources.
What is a virtual machine?
Virtual machines (VMs) are heavyweight software packages that provide emulation of low-level hardware devices, including CPU, Disk, and Networking. They encapsulate hardware and software components, creating a comprehensive snapshot of a computational system.
Full Isolation Security
Virtual machines operate in complete isolation as standalone systems. This ensures that each virtual machine remains immune to exploits or interference from other virtual machines running on a shared host.
While an individual virtual machine can still be susceptible to hijacking, its isolation prevents contamination of neighboring virtual machines.
Unlike containers, which are static definitions of dependencies and configurations, virtual machines offer a more dynamic and interactive development environment. Once the basic hardware definition is specified, a virtual machine can be treated as a bare-bones computer.
The software can be manually installed, and the current configuration state can be captured through snapshots. These snapshots allow for easy restoration or spinning up additional virtual machines with the desired configuration.
Building and regenerating virtual machines can be time-consuming due to their encompassing nature, involving a complete stack system. Modifying a virtual machine snapshot and ensuring expected behavior may require significant time for regeneration and validation.
Storage Size Cost
Virtual machines occupy substantial storage space, often growing to several gigabytes. This can result in disk space shortage issues on the host machine running the virtual machines.
Also read: Cloud Computing vs. Serverless Computing
Popular virtual machine providers
Virtualbox, owned by Oracle, is a free and open-source x86 architecture emulation system. It is a well-established platform and offers an ecosystem of supplementary tools to aid in developing and distributing virtual machine images.
VMware, a publicly traded company, is known for pioneering work in x86 hardware virtualization. It includes a hypervisor utility for deploying and managing multiple virtual machines.
In addition, VMware provides a robust user interface (UI) for virtual machine management and is a preferred option for enterprise environments with comprehensive support.
QEMU is a highly robust hardware emulation virtual machine option. It supports a wide range of generic hardware architectures. However, QEMU is a command-line utility without a graphical user interface for configuration or execution. This trade-off contributes to its reputation as one of the fastest virtual machine options available.
Which option is better for you?
When it comes to specific hardware requirements or the need to target different platforms, such as Windows and macOS, virtual machines (VMs) are the go-to solution. Virtual machines allow you to emulate and run an entire operating system with its associated hardware, providing a platform-independent environment. This makes VMs the ideal choice when you require precise hardware configurations or need to develop and test software on different operating systems.
On the other hand, for most "software-only" requirements where the focus is on running applications and services, containers offer a more efficient and lightweight solution. This is because containers encapsulate the necessary software dependencies and configurations, allowing applications to run consistently across different environments.
Containers provide isolation and portability without the overhead of emulating an entire operating system. As a result, they are particularly well-suited for deploying and managing software applications across various platforms, making them a versatile choice for most software development scenarios.
Virtual machines are preferred when specific hardware requirements or cross-platform compatibility are essential. Containers provide a streamlined and portable environment for running software applications across different systems. By leveraging the strengths of each technology, developers can effectively address both hardware-specific and software-oriented needs in their projects.
How can you use containers and virtual machines together?
The combination of containers and virtual machines can offer a flexible approach to resource virtualization, although its practical use cases may be limited in scope.
For example, a functional computational system can be established by creating a virtual machine that emulates a distinct hardware configuration and installing an operating system. Subsequently, a container runtime can be implemented on the operating system, enabling the deployment of containers.
One specific use for this configuration is experimenting with system-on-chip (SoC) deployments. Emulating popular SoC devices such as Raspberry Pi or BeagleBone development boards as virtual machines allows for testing containers on emulated hardware before deploying them on the devices.
This setup provides developers with a valuable opportunity to fine-tune containerized applications and ensure compatibility before real-world implementation. However, in most scenarios, containers or virtual machines alone will suffice for virtualization needs. The decision between the two depends on understanding resource requirements and the trade-offs involved in performance, isolation, and flexibility.
Virtualization plays a crucial role in modern application deployment and resource management, offering a range of options to suit different needs. Making the right choice can significantly enhance productivity and efficiency within your organization.
As experts in this field, we understand the complexities involved and are here to offer our expertise and guidance. Whether you are considering containers for their lightweight efficiency or virtual machines for their comprehensive isolation, we can provide tailored insights to help you make informed decisions.
Reach out to us today to discuss your virtualization needs and find the best solution for your organization's success.