What is Linux Server?

• Linux Server Definition

  Linux Server Definition

  Linux^® server refers to a specific type of server based on the free, open-source, and modular Linux operating system. Linux is often the preferred choice for web servers over other server operating systems, given the many benefits. These include cost-efficiency, powerful community support, freely-distributed source code, stability with lower risk of downtime, high performance in managing demanding workloads and storage needs, improved security from unwanted cyber threats, and customization flexibility in terms of server implementation and operation. Linux servers generally support popular databases such as MySQL^® and PostgreSQL^® and programming languages including PHP, Perl, and Python. Prominent companies leveraging Linux servers for their online services include Facebook, Twitter, Amazon, and Google.
• Linux Distrubutions

  Linux Distrubutions

  Linux has many community-developed and enterprise versions called Linux distributions, or distros, that come packaged with Linux Kernel, supporting programs, and libraries. Each of these versions offers a specific set of advantages to help meet different business requirements. While some work better for desktops, others are more suited for servers. Linux server distributions are lightweight and execute commands stripped-back and minimally using only the terminal without any graphical user interface (GUI). Linux server versions are extensively used across various scenarios such as web hosting services, application deployment, database management, network administration, etc. Outlined below are some popular Linux server distributions:

  Red Hat Enterprise Linux (RHEL)

  Red Hat^® Linux is one of the first and oldest Linux server distributions founded in 1993 by Marc Ewing. It was later discontinued in 2003 when Red Hat released the new Red Hat Enterprise Linux (RHEL) line. RHEL server distro is the most renowned paid open-source Linux server distro designed to meet the needs of the commercial market. Large enterprises use it for top-notch security, high stability, and reliability. RHEL server distribution guarantees enterprise-grade long-term support (LTS) of 10 years and is best-suited for cloud-based server infrastructure, large-scale application environments, and data centers. It offers a multitude of other paid exclusive tools and subscriptions.

  Fedora

  Fedora^® Server Linux is a free, community-supported Linux distribution sponsored by Red Hat. It’s often referred to as the “bleeding-edge” distro, given it offers all the latest server-based technologies. It gets frequent updates and has a short release cycle, making it less stable than RHEL. Fedora Server Linux distro brings many benefits, including modular packages, improved security with FreeIPA (a centralized authentication and identification security solution for UNIX/Linux environment), and better package management with support for YUM DNF, PackageKit, etc.

  CentOS Linux

  CentOS^® or Community Enterprise Operating System Linux has served as one of the most popular and widely accepted server distributions. Acquired by Red Hat in 2014, CentOS Linux distribution had been derived from RHEL source code. It’s stable, secure, and enterprise-focused, with free technical support driven by its community via mailing lists and web forums. CentOS Linux has long served as the primary choice for medium-to-large-sized web and server hosting companies. Its support for different management platforms, including cPanel, DirectAdmin, Plesk, ISPConfig, etc., helped manage multiple web-hosting sites on the server. CentOS Linux distribution reached end-of-life in December 2021. CentOS version 8 was the last and latest major CentOS Linux release. The focus has now shifted from the stable release of CentOS Linux to CentOS Stream, a rolling-release Linux distribution that serves as the upstream development branch of RHEL.

  Ubuntu Server

  Ubuntu™ Server is a widespread, open-source, free-to-download Debian-based Linux server distribution developed by Canonical. Ubuntu Server is preferred for its ease of use, affordability, security, and overall reliability. It delivers powerful scale-out performance for mission-critical workloads such as OpenStack Cloud deployments, massive render farm implementation, cluster setups, etc. Ubuntu Server offers a default five-year long-term support (LTS) covering hardware maintenance updates and interim release standard support for new features. It also provides the Extended Security Maintenance (ESM), extending the support lifecycle to up to 10 years. The latest Ubuntu Server 21.10 Linux Distro supports all major architectures such as x86-64, ARM v7, POWER8, IBM s390x (LinuxONE), RISC-V, etc. For enhanced security, the latest release enables two-factor authorization (2FA) and supports AppArmor3, a Mandatory Access Control (MAC) system for the Linux Kernel. Ubuntu Server supports a range of tools such as PHP, Apache2, GCC, Python, Open vSwitch, etc.

  Debian

  Founded in 1993, Debian^® is a free, open-source, lightweight, and community-supported Linux distribution serving as the base for many other popular Linux distros such as Ubuntu, PureOS, Tails, etc. Debian brings many advantages, including stability, long release cycles, simple installation, a vast package repository (over 59,000), and an extensive, helpful community for support and other resources. It offers three different versions of Linux distribution: Stable, Unstable, and Testing. Out of these three, Stable is the preferred choice by network and system administrators. It offers maximum reliability and security when running servers. However, this Linux distro variant comes with old packages such as KDE, GNOME, Xorg, etc. Debian Linux server distribution is compatible with different architectures, including alpha, amd64, i386, PowerPC, ARM64, etc. Network administrators can easily install Debian Linux distro over the internet via a Network Boot Image for server booting purposes. It also offers official cloud images across major cloud platforms. Furthermore, Debian provides the necessary tools and configuration to help IT administrators build their customized cloud images.

  openSUSE Linux

  openSUSE^® is an open-source community-developed project sponsored by SUSE Software Solutions, a German-based open-source software company. It’s known for its free, widely-used Linux distributions, namely openSUSE Leap (regular stable release with older software versions) and openSUSE Tumbleweed (rolling release with latest updates) targeted towards system administrators, enterprise developers, and openSUSE contributors, among others. Leap shares the core source code with SUSE Linux Enterprise (SLE), making it a more stable and mature choice to run servers at an enterprise level. openSUSE Linux server distros come with many advantages, including easy installation, extensive community support, and various tools such as Zypper package manager, YaST (Yet another Setup Tool) control center for system administration, Snapper for management of filesystem snapshots.

  SUSE Linux Enterprise Server (SLES)

  Based on the open-source openSUSE Linux distro and developed by SUSE, SLES is targeted towards enterprise-level business-critical operations. It is highly stable, and its components undergo rigorous testing to be enterprise-ready. It focuses on security, long-term support, easy handling, and long release cycles (three to four years) instead of bleeding-edge updates. Like OpenSUSE, SLES uses Zypper for package management and YaST to manage system configuration and installation tasks such as updating packages, implementing an FTP server, setting up containers, changing firewall settings, etc.

  Its latest SLES 15 SP3 release supports full binary compatibility with community Linux distribution, openSUSE. SLES supports processor platforms such as x86-64, ppc64le, s390x, and ARM v8. SLES is used by many leading companies such as SAP, Bosch, Experian, VMware, Amazon, etc.
• Linux Server Monitoring Best Practices

  Linux Server Monitoring Best Practices

  While Linux servers are known for their flexibility, stability, and scalability, it’s common for system administrators to face performance constraints related to storage, memory, and network. Server failure can significantly degrade the overall quality of service offered. Linux server monitoring refers to a set of techniques and tools used to identify bottlenecks, resolve issues faster, and analyze the server’s resource consumption for optimal server performance. The following are some best practices for server monitoring:

  • Keep tabs on crucial server performance metrics, including CPU usage, system load, memory consumption, virtual memory utilization, disk I/O, network bandwidth, and application availability. This will help analyze the overall Linux server health and troubleshoot faster.
  • Learn necessary monitoring commands for better visibility. Some of these commands include iostat (shows storage statistics), mpstat (reports processor statistics), tcpdump (analyzes data-network packet), free (data about used and unused memory), meminfo (displays memory usage data), etc.
  • While the lightweight, agentless monitoring approach is best-suited for servers, it’s equally important to understand the advantages of agent-based monitoring to choose the right and efficient approach per specific business requirements.
  • Leverage automated server and application monitoring tools for efficient, simplified, and real-time tracking of Linux server performance. These tools provide visibility across complete application infrastructure and help dig deeper into server performance issues to isolate the root cause and provide quick resolution. IT admins can further monitor resource utilization (CPU load, memory usage, disk capacity, etc.) and hardware health (temperature, fan speed, power supply, etc.) using these tools. Some tools also offer out-of-the-box templates to analyze databases, web servers, application servers, etc., using SNMP, JMX, WMI, and CIM protocols.
  • Ensure the automated monitoring tools offer dedicated Linux server monitoring functionalities to diagnose delayed response time, latency, or packet loss issues. These tools must support the common Linux server distributions such as RHEL, Fedora, CentOS, SLES, Debian, etc.
  • Use tools with the flexibility to select between agent-based and agentless server monitoring. Also, set automated alerts for CPU overloads, insufficient memory, and hardware issues to help with better capacity planning and avoid server downtime.