This article walks through checking whether Git is installed, detecting the Linux distribution, installing Git via apt‑get or yum, configuring user information, generating SSH keys, cloning a repository, and provides a concise list of essential Git commands for everyday version‑control tasks.
This guide explains why manual log inspection is tedious, introduces Logwatch as a solution, and provides step‑by‑step commands to install it on CentOS, configure its settings, run analyses instantly, and interpret the generated reports.
This article provides a comprehensive comparison between CentOS and Ubuntu, covering their histories, advantages, disadvantages, package management systems, software repositories, community support, and typical use cases, to help readers choose the most suitable Linux distribution for server or desktop environments.
This article traces the evolution of CentOS within the Linux ecosystem, explains the shift to CentOS Stream, outlines the end‑of‑life schedule, and evaluates various replacement distributions—including Rocky Linux, Ubuntu, Oracle Linux, and several Chinese OS projects—providing guidance for different enterprise and development scenarios.
The article analyzes why a Java service repeatedly crashes around midnight in test environments, tracing the issue through system limits, Java version checks, cron job execution, strace logs, and Linux OOM killer behavior, and finally proposes configuration and version upgrades to prevent the failures.
This article explains what Firewalld is, outlines its key features such as zones, runtime versus permanent settings, services, and dynamic updates, and provides step‑by‑step commands to create firewall rules that limit access to an Nginx server on port 8088 to a single IP address while leaving other ports unrestricted.
This article explains the concepts and advantages of NoSQL databases, categorizes the four main types, introduces MongoDB’s data model and components, and provides step‑by‑step instructions for installing MongoDB 7.0 on CentOS 7 using both yum repository and manual RPM packages.
This guide walks you through installing phpIPAM—a web‑based IP address management tool—by preparing the server environment, configuring Apache and MariaDB, downloading the source code, setting permissions, and completing the web‑based setup, all with detailed commands and screenshots.
This step‑by‑step guide shows how to install and configure Docker on CentOS 7, optionally set up docker‑compose, pull a Tomcat image, build a Spring Boot project, package it, and run it inside a Docker container, including commands for mounting, port mapping, and verifying the deployment.
This guide explains how to use Firewalld on CentOS to create zones, services, and rich rules that restrict access to specific ports for designated IP addresses, covering installation checks, rule creation, dynamic updates, and verification commands for comprehensive firewall management.
The article examines Red Hat's decision to close RHEL source access, traces the historical relationship between CentOS and RHEL, explains how CentOS Stream now receives updates via community feedback, and evaluates Ubuntu Pro's long‑term support as an alternative for enterprise cloud deployments.
The article explains that CentOS 8 stopped receiving updates in December 2021, recommends using CentOS 7 (supported until June 2024), and details the various ISO variants and download sources for CentOS 7.
This guide explains why log analysis is essential for Linux system health, walks through installing Logwatch on CentOS, configuring its core settings, automating daily runs via cron, and interpreting sample output for connections, SSH activity, package installs, and disk usage.
This article provides a step‑by‑step guide for Windows users to install VSCode, set up a VMware‑hosted CentOS 7 VM, compile the MySQL 8.0.34 source with debug options, configure VSCode remote‑debugging plugins, and perform source‑level debugging of MySQL.
Three major IT companies—SUSE, Oracle, and CIQ—have formed the Open ELA alliance to provide source code for RHEL‑compatible downstream Linux distributions, offering a community‑driven alternative after Red Hat’s termination of CentOS, aiming to ensure stable, secure, and freely redistributable enterprise Linux.
This tutorial walks through a complete, step‑by‑step setup of a one‑click CI/CD pipeline that installs Docker and Jenkins on CentOS, configures Maven, creates a Jenkins job, builds a Spring Boot JAR, packages it into a Docker image, and runs the container, providing all commands and screenshots for a seamless deployment experience.
This guide explains three practical methods—using crontab, rsync, and mysqldump—to set up scheduled backups of PHP website files and databases on a CentOS server, ensuring data protection through automated daily or periodic tasks.
This guide outlines how to achieve robust security for a PHP website on CentOS by updating the system, configuring Firewalld, installing and hardening PHP, enabling HTTPS, and implementing regular data and database backups.
This tutorial explains how to install Google Chrome and ChromeDriver on CentOS, use PHP‑WebDriver to scrape dynamic web pages, and introduces XPath syntax for locating elements, providing step‑by‑step commands, code samples, and execution results.
This article walks through installing Nginx on CentOS, configuring DNS across three servers, applying common Nginx hardening techniques such as version hiding, log rotation, connection keep‑alive tuning, image caching, and implementing anti‑hotlinking to protect site resources.
Learn how to set up a complete CI/CD pipeline on CentOS 7 by installing Docker and Jenkins, configuring Maven, creating Dockerfiles, and automating the build, test, and deployment of a Spring Boot application with detailed commands, screenshots, and best‑practice tips.
This tutorial walks you through a complete one‑click Jenkins, Docker, and SpringBoot automated deployment on CentOS, covering environment preparation, Docker and Jenkins installation, plugin configuration, job creation, build testing, and running the packaged application in a Docker container.
This guide explains what SELinux is, how its mandatory access control policies enforce security, the risks of disabling it, and provides step‑by‑step instructions for turning it off on CentOS while suggesting the permissive mode as a safer alternative.
This guide walks you through installing Docker, Docker Compose, OpenSSL, and the Harbor private registry on CentOS, configuring Harbor, setting up insecure registries, and using Docker and Helm commands to push and pull images.
A friend’s CentOS 7 server failed to boot because the LVM‑managed root partition disappeared, and this guide walks through diagnosing the dracut error, extracting partition data from raw disk sectors, recreating the LVM backup file, and restoring the system to a bootable state.
CentOS's end-of-life announcement has sparked significant discussion in China's tech community, with experts viewing it as a catalyst for domestic OS development despite short-term challenges.
This article introduces iptables, explains its core concepts such as chains, rules, and tables, demonstrates common commands for listing, adding, deleting, and modifying rules, and presents a step‑by‑step firewall configuration case for securing jump‑hosts on CentOS systems.
This guide walks you through enabling firewall services, adding permanent ports, and reloading rules on CentOS 7 using firewalld, as well as editing iptables files and restarting the firewall on CentOS 6, complete with command examples and common pitfalls.
This guide walks through enabling the firewall, opening specific ports, and reloading rules on CentOS 7 using firewalld and on CentOS 6 using iptables, providing exact commands, optional parameters, and troubleshooting tips for successful network configuration.
This guide walks through preparing two CentOS virtual machines, installing Nginx, explaining high availability concepts, and configuring Keepalived with VRRP to achieve automatic failover and virtual IP management for a resilient Nginx service.
This guide walks through preparing two CentOS VMs, installing Nginx, explaining high‑availability concepts, and configuring Keepalived with VRRP and a health‑check script to achieve automatic failover of Nginx services via a virtual IP.
This guide explains why CentOS 7 reaches end‑of‑life, compares community and domestic replacements, and provides detailed automatic and manual procedures—including Leapp workflows and RPM handling—to upgrade CentOS 7 to a suitable modern distribution while meeting compliance and hardware requirements.
This tutorial walks you through setting up a complete Jenkins‑Docker‑SpringBoot CI/CD pipeline on CentOS 7, covering Docker and Jenkins installation, plugin configuration, Maven setup, job creation, automated building, Docker image creation, and final verification, all with practical command examples.
This article walks through the fundamentals of Linux log management by introducing Rsyslog, showing how to install it on CentOS, configure facilities and severity, and demonstrate practical examples for aggregating web server access logs to a central application server.
This guide explains how to enable and configure Linux firewall ports on CentOS 7 using firewalld and on CentOS 6 using iptables, covering status checks, opening specific ports, reloading rules, and common troubleshooting tips such as service listening verification.
This guide shows how to install ImageMagick on CentOS 8, use the convert command to change image formats, batch‑process files with a Bash script, rotate or flip images, append pictures, and resize them, providing practical command‑line examples and tips.
The article explains why CentOS is being phased out, outlines the advantages of adopting AlmaLinux as a stable, RHEL‑compatible replacement, describes its migration tools and community support, and compares other viable CentOS alternatives such as Rocky Linux and Oracle Linux.
This guide explains step‑by‑step how to check firewall status, start firewalld, open specific ports, reload or restart the firewall on CentOS 7, and modify iptables directly on CentOS 6, including useful commands for listing, removing, and temporarily disabling ports.
This guide walks you through installing Podman on CentOS 8, configuring user namespaces, creating and building a custom UBI‑based image with a Dockerfile, running containers, verifying installed tools, using interactive shells, and mounting host directories for persistent storage.
This guide walks you through checking firewall status, enabling firewalld, adding permanent ports, reloading the firewall, and using iptables on CentOS 6, providing complete command examples and tips for troubleshooting common issues.
This guide explains step‑by‑step how to check firewall status, enable firewalld, open specific ports, reload or restart the firewall, and modify iptables on CentOS 6 and 7, including useful commands and common pitfalls.
This guide walks through preparing the environment, installing and configuring Elasticsearch, Logstash, Kibana, Kafka, and Filebeat on a CentOS 7 system, including necessary code snippets, user permissions, and troubleshooting tips for a fully functional logging and data pipeline.
The article explains how a MySQL 5.7 service fails to start on a CentOS 7.9 server because SELinux blocks write access to err.log, walks through log inspection, strace tracing, SELinux context analysis, and provides a simple fix by disabling SELinux.
This guide lists popular Linux text editors and IDEs—including Vim, Nano, Geany, Emacs, Sublime Text, Atom, Brackets, Komodo Edit, gedit, and Qt Creator—provides brief feature overviews, official website links, and step‑by‑step installation commands for both Ubuntu/Mint (apt) and CentOS (yum).
This guide shows how to monitor disk usage on a CentOS 7 server, collect periodic snapshots with iostat, sar and pidstat, troubleshoot atd scheduling issues, and finally use SystemTap to pinpoint the exact PID that writes to a specific file, providing complete scripts and command‑line steps.
This step‑by‑step guide shows how to prepare three CentOS 7 nodes, install containerd, configure system settings, deploy kubeadm/kubelet/kubectl, initialize a Kubernetes v1.22.1 control plane, add worker nodes, install the flannel CNI plugin, set up the Dashboard, and clean up the environment.
This article explains why CentOS 7 is reaching end‑of‑life, reviews community and domestic alternatives such as Rocky Linux, AlmaLinux, Anolis OS, openEuler and Galaxy Kirin, and provides detailed automatic (Leapp) and manual (dnf distro‑sync) upgrade procedures with code examples for a smooth migration.
This guide walks through installing Docker and Jenkins on CentOS 7, configuring Jenkins with necessary plugins, setting up Maven, creating a Jenkins pipeline to pull, build, and containerize a Spring Boot project, and finally testing and running the application automatically, providing a complete one‑click CI/CD solution.
This guide provides step‑by‑step instructions for installing Docker on CentOS and Ubuntu, configuring image accelerators for faster pulls, and using Docker commands to pull, run, list, and clean up images and containers, including tips for handling dangling and intermediate layers.
This guide provides step‑by‑step instructions for installing Docker on CentOS and Ubuntu, configuring accelerated image mirrors, managing Docker images—including listing, tagging, and removing—while covering essential commands, storage considerations, and best practices for both systemd and upstart environments.
This article surveys the major Chinese open‑source Linux distributions that serve as CentOS replacements—including OpenEuler, Anolis OS, UnionTech UOS, Alibaba Cloud Linux, TencentOS, KylinOS, Deepin, Red Flag and Ubuntu‑Kylin—detailing their origins, compatibility, key features, and typical cloud or enterprise use cases.
This guide walks you through checking your current CentOS 8 environment, downloading the Oracle‑provided centos2ol.sh script, executing it to replace packages and switch kernels, and verifying the successful migration to Oracle Linux Server with the Unbreakable Enterprise Kernel.
This step‑by‑step guide explains how to verify your CentOS 8 environment, download and prepare Oracle's centos2ol.sh migration script, run it to replace packages and switch to the Oracle Linux kernel, reboot, and confirm the successful migration to Oracle Linux Server with UEK.
This guide explains why you should avoid compiling GCC yourself and shows step‑by‑step how to use Red Hat's Developer Toolset or gcc‑toolset to install, switch, and activate newer GCC versions on both CentOS 7 and CentOS 8, including temporary and permanent activation methods.
This article reviews the major domestic Linux distributions that can replace CentOS, such as OpenEuler, Anolis OS, Alibaba Cloud Linux, TencentOS Server, KylinOS, and deepin, highlighting their compatibility, performance optimizations, and suitability for public, private, and hybrid cloud deployments.
This article explains why CentOS 8 reached end‑of‑life, introduces CentOS Stream, and reviews seven server‑grade Linux distributions—including Ubuntu, Oracle Linux, openSUSE, AlmaLinux, Rocky Linux, VzLinux, and Springdale Linux—as viable replacements for CentOS 8 in 2022.
This guide walks you through installing epel, xrdp, and tigervnc‑server on a CentOS 8 virtual machine, configuring SELinux and the firewall, enabling the XRDP service at boot, and finally connecting from Windows 10 using the built‑in Remote Desktop client.
This guide walks through installing the GNOME desktop, adding the Xrdp package, configuring the service, opening firewall ports, and verifying remote desktop connections from Windows, enabling seamless RDP access to a CentOS 7.9 server.
The article reviews the end of CentOS, introduces the newly released RHEL 8.6, AlmaLinux 8.6 and Rocky Linux 8.6, compares their components, platform support, and community backing, helping readers decide which RHEL‑compatible distribution fits their needs.
This article provides a comprehensive tutorial on why to use Elasticsearch, how to pull the Docker image, set up data directories, configure cluster and node settings, adjust system limits, launch three Elasticsearch containers, and verify the cluster using REST APIs and the elasticsearch‑head UI.
This guide walks through setting up the GitLab CE repository, installing GitLab, generating SSL certificates, configuring GitLab and Nginx for HTTPS, and verifying access on a CentOS server using command‑line operations.
This guide walks through installing PostgreSQL 14 on a CentOS server via a shell script, covering repository setup, package installation, initialization, user and database creation, remote‑connection configuration, firewall adjustments, service verification, and connecting with Navicat.
This guide explains how to install the ncat package on CentOS 7/8, use it to check TCP connections, set up listening ports, run a basic chat service, probe SSH versions, create a backdoor, and serve static web pages, providing concrete commands and example outputs for each task.
This step‑by‑step guide shows how to set up both single‑node and multi‑node Citus clusters on Docker, Ubuntu/Debian, and Fedora/CentOS/Red Hat, covering repository addition, package installation, configuration of shared_preload_libraries, database initialization, worker node registration, and verification commands.
This tutorial introduces Cockpit, the web‑based visual management tool bundled with CentOS 8, and provides detailed installation, repository configuration, service activation, and feature walkthroughs to help administrators manage users, firewalls, storage, containers, and updates without using the command line.
This article introduces the built‑in Cockpit web console for CentOS 8, explains how to install and configure CentOS 8, set up Cockpit, and demonstrates its various management functions such as system overview, storage, networking, containers, user accounts, updates, and SELinux control.
Learn how to install, configure, and use Cockpit—a built‑in web‑based visual management tool in CentOS 8—to handle user accounts, firewalls, storage, monitoring, container management, and software updates, with step‑by‑step commands, repository tweaks, and practical screenshots.
This guide explains why and how to disable SELinux on CentOS, covering status checks, temporary and permanent disabling methods, necessary configuration file edits, and verification steps to ensure the system runs without SELinux enforcement.
This tutorial walks you through checking disk usage, adding a new disk, creating a physical volume, extending the volume group and logical volume, and finally resizing the XFS filesystem on a CentOS system to successfully enlarge the root partition.
This tutorial explains how to set up the Hue web UI on a CentOS 7 machine by installing required dependencies, compiling Hue, configuring HDFS, YARN and Hive integration files, starting Hive services, launching Hue, and accessing the interface, with all commands and configuration snippets provided.
When a Longhorn volume fails to mount on a CentOS 7.6 node with the error ‘fsck found errors on device’, you can diagnose the issue via pod logs, download and install a newer e2fsck, then run fsck.ext4 with appropriate options to repair the filesystem and restore the volume.
This tutorial walks through installing and configuring PostgreSQL 12 with TimescaleDB on a CentOS 7.5 server, covering kernel tweaks, required packages, compilation, initialization, start/stop commands, remote access setup, and user‑role management for a production‑ready time‑series database.
This guide walks you through setting up a CI/CD environment on a CentOS server using Docker, Git, Java, and Jenkins, covering installation, configuration, plugin management, and practical examples such as building Docker images, deploying a React app with Nginx, and automating the entire pipeline.
Red Hat will discontinue free CentOS Linux at the end of 2023, moving CentOS 8 to end‑of‑life on December 31, while CentOS 7 receives support until June 30 2024, and users are urged to consider alternatives such as AlmaLinux, Rocky Linux, or RHEL.
Red Hat announced the end of free CentOS Linux, detailing the 2023 EOL for CentOS 8, the shift to CentOS Stream, extended support for CentOS 7, and offering migration options such as AlmaLinux, Rocky Linux, and RHEL for enterprises seeking stable server platforms.
This article demonstrates how to use Ansible playbooks and simple shell scripts to identify the CentOS major version and system architecture, while also providing promotional links to related DevOps and Kubernetes tutorials.
The article explains that CentOS Linux 8 reaches its end of life on December 31, 2021, details the shift to CentOS Stream, outlines the extended support timelines for CentOS 7, and lists alternative enterprise‑grade Linux distributions such as AlmaLinux, Rocky Linux, and others.
Red Hat confirmed that CentOS Linux 8 will reach its End of Life on December 31, 2021, shifting the CentOS project to the developer‑focused CentOS Stream platform and outlining support timelines, migration options, and alternative distributions for enterprise users.
This tutorial demonstrates how to create a Dockerfile on a CentOS host, build an Nginx image, run the container, and verify its operation, while highlighting the importance of specifying an entrypoint or CMD in the Dockerfile.
This guide walks through setting up BIND9 in a chroot environment, configuring ACLs and views for intelligent DNS routing, creating master and slave zones, and testing resolution on CentOS 8, providing a practical solution for secure and segmented DNS services.
This article provides a step‑by‑step tutorial for setting up a MySQL database on a CentOS server, covering database creation, import, phpMyAdmin installation and configuration, Navicat installation and activation, opening required ports, and configuring remote user access for successful connections.
This step‑by‑step guide shows how to set up Docker on CentOS 7, install Docker Compose, pull a Tomcat image, create a Spring Boot project, package it, and run it inside a Docker container using both Tomcat and OpenJDK images.
This article provides a comprehensive, hands‑on tutorial for installing and configuring Zabbix 5 on CentOS 7, covering system overview, key terminology, disabling SELinux and firewalls, setting up repositories, installing server, agent, frontend, MariaDB, database initialization, configuration tweaks, and final web‑UI setup.
Learn how to install Sipcalc on CentOS 8, then use its powerful commands to calculate IPv4 and IPv6 subnets, display network masks, broadcast addresses, and binary representations, with step‑by‑step examples including CIDR, classful, and extended range queries.
This comprehensive tutorial walks through preparing a CentOS 7 host, configuring hostnames, disabling swap and firewalls, installing Docker and Kubernetes components with kubeadm, setting up the master and worker nodes, deploying the flannel network plugin, testing with nginx, and installing the Kubernetes dashboard, all with detailed commands and troubleshooting tips.
Learn how to set up Kafka on CentOS, create and manage topics, adjust partitions, produce and consume messages using command‑line tools and Java code, and explore related utilities such as consumer groups, log inspection, and configuration tips for remote access.
This comprehensive tutorial walks you through installing Zabbix on CentOS 7, covering system overview, key terminology, disabling SELinux and firewalls, setting up repositories, installing server, agent, frontend, MariaDB, configuring the database, and finalizing the web interface with screenshots.
This guide walks you through setting up a three‑node etcd cluster on CentOS 7 using static configuration and self‑signed TLS certificates, covering member addition and removal, data backup via snapshots, and full cluster restoration from those snapshots.
The article explains that CentOS 8 will cease maintenance next year, ending the free RHEL rebuild, introduces CentOS Stream as a rolling‑release bridge between Fedora and RHEL, and outlines the impact on CentOS 7 and the need to consider alternative distributions.
This article walks you through the complete installation and configuration of UCloud's free USDP (UCloud Data Platform) on a three‑node CentOS 7.2‑7.6 cluster, covering environment preparation, package download, repair scripts, MySQL setup, service startup, web UI activation, monitoring, and a quick Hive query example.
This guide explains the NFS (Network File System) protocol, its reliance on RPC, the ports it uses, how to activate the required daemons, differences among NFSv2/v3/v4/v4.1, and provides step‑by‑step instructions for installing, configuring, and mounting NFS on CentOS 7, including firewall and export settings.
This guide walks through setting up Kafka on CentOS, creating and configuring topics, inspecting topic and consumer group details, adjusting partitions, and implementing Java producer and consumer applications, complete with command-line examples, code snippets, and troubleshooting tips for remote server access.
This comprehensive tutorial walks through preparing the environment, configuring yum repositories and hosts, installing Oracle Grid Infrastructure with ASM disk groups, creating ASM disks, and finally building an Oracle database on a CentOS 7 system, including command examples and GUI steps.
This guide explains the NFS protocol fundamentals, activation steps, version comparisons, and provides a step‑by‑step CentOS 7 installation and configuration tutorial, including service setup, firewall adjustments, export file editing, and client mounting procedures.
This tutorial explains how to download a CentOS 7 Docker image, run it as a lightweight Linux virtual machine, map ports and directories, access the container's shell, and export or import the container as an image for easy migration across hosts.
This guide explains what Chrony is, its components and advantages, walks through installation and configuration on CentOS 7, and demonstrates essential chronyc commands for monitoring and managing system time synchronization.
This comprehensive tutorial walks you through preparing the environment, configuring the OS, setting up ASM disk groups, installing Oracle Grid Infrastructure, creating ASM disks, and building a database on a CentOS 7 cluster, complete with detailed screenshots for each step.
This guide walks you through preparing a CentOS 8 environment, installing JDK, Zookeeper and Kafka, configuring each service with proper data directories and ports, and automating startup using shell scripts for a three‑node Zookeeper cluster and a three‑node Kafka cluster.
This guide demonstrates how to achieve high availability for Nginx by deploying Keepalived in a virtual IP failover setup, covering installation via yum or source, configuration of keepalived and VRRP scripts, service management, and verification steps on two CentOS servers.
This step‑by‑step guide shows how to install JDK 1.8, download the Jenkins RPM (from the official site or a Tsinghua mirror), install it, modify the config to run as root on port 8888, start the service, retrieve the initial admin password, and complete the Jenkins setup on a CentOS system.
