What is a Linux Server?

Today, Linux server operating systems power many large, complex data centers and workload environments, including bare metal servers, virtual machines (VMs),  containers and both private and public cloud ecosystems.

Linux servers can operate on physical devices or be deployed virtually, and they are known for their scalability, flexibility and performance. Linux servers can be run on a variety of common devices, such as laptops, routers or smartphones. Many of the top global enterprises deploy Linux servers for a range of functions, including networking, data sharing, database management and more.

Linux is an open-source operating system (OS) based on Unix that was invented in 1991 to provide a free alternative to proprietary systems like Microsoft Windows and mac OS. Today, Linux has become one of the most popular operating systems in the world.

In the mobile phone market alone, Linux’s mobile OS, Android, holds 71% of the global market share. Linux operating systems rely heavily on the Linux kernel, a free, open-source computer program that gives a user control over the hardware and software layers of a computer system.  

The Linux kernel forms the core of the Linux operating system, acting as a bridge between components and enabling them to be controlled by a user. Kernels give an OS most of its functionality and have been referred to as ‘the beating hearts’ of computer systems. In the case of the Linux kernel, it is made up of computer code that allows various components, such as system libraries, user space utilities and applications, to communicate with the OS and subsequently the user.

Linux distributions are versions of the Linux code that are released every 9-10 weeks by a global community of developers. One of the aspects that has made Linux so successful is the way it is constantly maintained and improved upon, with each update to its code adding some new functionality or compatibility. Each new Linux distribution, or “distro” as they are called, is known as a “stable kernel” and is added to a repository of Linux distributions that is maintained at kernel.org and on GitHub. Some of these offer certifications to users that can demonstrate proficiency with a specific Linux version.

Linux distributions are open and free to any user, some of the most popular have their own names, such as Fedora, Ubuntu and Linux mint. Servers that run a specific Linux distribution are typically known by that distribution. For example, in the case of a server running Ubuntu, it is referred to as a Ubuntu server.

Linux servers are built on a modular design, an approach to software development that breaks down large, complex systems into smaller, self-contained units. Modular design is one of Linux’s key features because it enables the constant versions of Linux being offered by the global community of global developers. While each Linux distro is based on the Linux kernel, kernel versions and modules can vary.

• Versions: Users can customize each Linux OS to their specific needs, making it one of the most flexible operating systems available. For example, if a user needs to work with artificial intelligence (AI), they can run the newest version of Linux OS that has updates making it compatible with the latest technologies. However, if they need more reliability and stability, and are willing to sacrifice compatibility with newer technologies, they can simply opt to run an older version. Some of the most popular Linux versions are Ubuntu, Debian, CentOs and IBM Red Hat Enterprise Linux (RHEL).

• Modules: Modules, also known as kernel modules, are software applications that can be put on a kernel or taken off to extend its compatibility with certain devices and systems without rebooting. Once the kernel module is installed, the OS will recognize the device and support its use often through a component known as a driver. For example, a file system driver relies on code that gives the kernel specific functionality when interacting with different file systems.

All devices that run the Linux OS rely on these three simple steps. 

1. Initiating the boot process: Once the boot process has been initiated, the BIOS (Basic Input/Output System) the firmware the computer uses to manage data flow between the OS and various devices loads a program known as a bootloader. The bootloader locates the Linux kernel image on the hard disk and puts it into memory, enabling it to take control of the system.
2. Managing input/output: The Linux OS manages input/output through “streams” channels that send and receive basic commands such as “standard input,” “output” and “error.” The Linux kernel depends on streams to control data exchange between all applications and external components, such as keyboards, a mouse, a camera or a printer, by sending all commands through a driver.  
3. Using Linux command line interface (CLI): CLIs are text-based methods for users to control an operating system from a keyboard. The Linux CLI lets users type in simple commands that access and control a system’s resources. For example, typing “cd,” which represents “change directory,” enables users to access various directories on the system, such as directories containing documents, applications and more.

From reducing operating costs in data centers, to decreasing application downtime, to pairing with the latest cutting-edge mobile technologies, here are a few of the most widely recognized benefits of Linux servers.

As one of the most widely-used operating systems installed on servers worldwide, the Linux OS and Linux servers have many enterprise use cases. Here are a few of the most popular.

The Linux OS is considered foundational to cloud computing environments, and Linux servers power many public and private clouds, including AWS, Google Cloud Platform, Microsoft Azure and more. Cloud infrastructure, like VMs and storage, depends on Linux servers’ scalability and cost-effectiveness, as well as their compatibility with other technologies.

The Linux OS supports more web servers than any other OS in the world, with one recent study showing that 96% of the top million web servers globally rely on it. Linux servers support many popular software-as-a-service (SaaS) web server solutions like Apache and Nginx, enabling it to support a diverse range of sites, including blogs, ecommerce and video streaming.

Many large organizations host their most critical business applications on Linux application servers, including collaboration solutions, messaging platforms and productivity tools. Enterprise Resource Planning Systems (ERPs), for example, are often hosted on Linux servers, helping integrate and automate core business processes like finance, HR, manufacturing and delivery. Customer Relationship Management (CRM) software, like SalesForce and Hubspot, rely on Linux servers to help customers analyze and better use their customer data.

Many enterprises rely on Linux servers to manage large, complex databases. Linux is compatible with many popular SaaS database solutions like MySQL and MongoDB, and its stability and high performance make it a strong choice for database management.

DevOps teams rely on Linux servers for their high uptime capabilities, security and flexibility. Linux servers can host many popular DevOps tools, such as Jenkins and Ansible, that help improve software pipelines through automation, testing and deployment. A recent study by Statista showed that 47% of developers worldwide run Linux OS on their servers.

Virtualization is the process of dividing computer components like processors and memory into VMs that can be used virtually by anyone. Linux supports virtualization with its own hypervisor (software that enables multiple VMs to run on a single server) called kernel-based virtual machines (KVMs). KVMs allow users to run versions of Linux tailored for a specific workload or purpose, such as sharing memory or other compute resources. There are many popular organizations that offer Linux virtualization, including VMware, VirtualBox and KVM/QEMU.

Linux servers underpin many big data analytics solutions, including Hadoop, Apache Spark and Apache Kafka. A Linux server’s stability and performance make it a strong choice for meeting large-scale data processing requirements, and its robust security features mean that it can handle even the most sensitive kinds of data.

A Linux server’s lightweight nature make it a strong solution for many Internet of Things (IoT) applications, such as smart devices and scalable automation. Unlike many proprietary operating systems, Linux is highly customizable and can be tailored to meet the unique configurations of complex IoT systems like smart vehicles, air-quality monitoring systems, biomedical devices and more.