This guide walks through using the Crash utility to parse a kdump vmcore, locate the sk_buff structure, examine its fields, and trace related socket data, illustrating a practical approach to diagnosing kernel memory corruption.
This article explains how to identify the causes of increased network latency on Linux servers using tools such as ping, traceroute, hping3, wrk, tcpdump and Wireshark, demonstrates a practical case with two Nginx containers, analyzes TCP delayed ACK behavior, and provides actionable steps to measure, trace, and mitigate latency.
Linux kernel 5.19, announced by Linus Torvalds on June 6, marks a multi‑platform milestone with extensive driver updates, AMD GPU support, new LoongArch64, Apple NVMe, Intel GPU groundwork, and HPE GXP architecture, while preserving stability and signed pull‑request integrity.
eBPF is a kernel‑level sandbox technology that enables safe, high‑performance, programmable instrumentation for networking, security, and observability, and this article answers seven key questions covering its definition, applications, origins, usage steps, implementation details, best practices, and current ecosystem.
This article explains the difference between CPU load and CPU usage, then shows step‑by‑step how to calculate CPU utilization on Linux using vmstat, parsing /proc/stat, and extracting idle percentages from top, with ready‑to‑run command examples for both single‑core and multi‑core systems.
This guide explains how to use the Linux ss command to view socket information, covering basic usage, options for filtering TCP/UDP/UNIX sockets, suppressing headers, showing listening sockets, summarizing statistics, and preventing DNS resolution, with concrete command examples and output screenshots.
Although TCP provides reliable transmission, its guarantees have limits—such as incomplete CRC checks, process crashes before data reaches the transport layer, possible ISP tampering, and kernel‑level ACKs that don’t ensure user‑space receipt—so large downloads must still be validated for full integrity.
This article presents a series of images that quickly review essential C++ backend development topics, highlighting low‑level concepts such as memory management, inter‑process communication, network programming, and the importance of databases and Linux, while comparing C++ to Java backend routes.
This guide explains how to install, start, and stop the crontab service, configure global and user-specific cron directories, write crontab entries with proper syntax, and apply advanced techniques such as output redirection, nohup, background execution, and date-based log naming for reliable Linux task automation.
This article explains Linux virtual memory, the page‑fault allocation process, the two memory‑reclaim paths (kswapd and direct reclaim), OOM killer scoring, swappiness tuning, NUMA‑aware reclamation, and practical steps to protect critical processes from being killed.
This article introduces systemd, explains its features and unit file syntax, and provides step‑by‑step practical examples for managing Nginx, Tomcat, and custom Java JAR services with systemd on modern Linux distributions.
This comprehensive guide introduces shell programming fundamentals, demonstrates how to write, execute, and manage scripts, explains variables, strings, parameters, arithmetic, control structures, functions, arrays, and file inclusion, and provides practical code examples for Linux environments.
This guide explains how Zabbix agent monitors Linux and Windows systems, compares active and passive modes, and provides detailed optimization tips for OS metrics, CPU, memory, filesystem, Windows services, performance counters, and event logs, including alarm suppression and macro usage.
Ubuntu 22.04 LTS "Jammy Jellyfish" introduces twenty notable updates—including Wayland as the default display server, a light‑by‑default theme, a more compact desktop UI, improved icons, horizontal workspaces, revamped app launcher, dock tweaks, new accent colours, touch‑pad gestures, password‑protected zip handling, mic mute alerts, calendar events in the notification area, enhanced power options, battery‑percentage display, a clear restart option, refined keyboard shortcuts, multitasking settings, an interactive screenshot tool, a true dark mode, and Firefox now delivered as a Snap package—all aimed at a smoother, more modern user experience.
Ubuntu 22.04 LTS introduces a default Wayland display server, a lighter Yaru theme, a more compact GNOME desktop, enhanced desktop icons, horizontal workspaces, revamped app launcher, dock refinements, new accent colours, touch‑pad gestures, password‑protected zip handling, microphone mute alerts, calendar events in the notification area, expanded power‑management modes, visible restart option, improved keyboard shortcuts, extensive multitasking settings, a new interactive screenshot tool, proper dark mode, and Firefox distributed as a Snap package.
This article explains Linux virtual memory concepts, the process of memory allocation, page fault handling, background and direct memory reclamation methods, LRU-based page types, NUMA considerations, tuning parameters like swappiness and min_free_kbytes, and strategies to prevent OOM killer termination.
Ubuntu 22.04 LTS ‘Jammy Jellyfish’ introduces 20 desktop enhancements—from Wayland as the default display server and a lighter Yaru theme to revamped workspaces, dock, power options, and a native Snap‑based Firefox—making the desktop more intuitive, compact, and feature‑rich.
NVIDIA has finally open‑sourced its Linux GPU kernel driver, a landmark move that promises tighter OS integration, easier debugging, and broader support for Turing and Ampere GPUs, while also reshaping the relationship between proprietary drivers, the Nouveau project, and major Linux distributions.
The article explains how the Linux kernel translates ARM GIC hardware interrupt numbers into virtual software IRQs by maintaining a global bitmap, initializing the interrupt controller, using irq_domain structures to map and associate hwirq and virq values, and storing relationships in descriptor and revmap trees for efficient lookup.
The article explains why a 100 GB file can be copied in under a second by examining the difference between logical file size and physical block usage, demonstrating sparse file behavior, inode structure, direct and indirect block indexing, and how these mechanisms affect copy performance on Linux.
This article provides a comprehensive, step‑by‑step tutorial for installing and configuring the phpIPAM IP address management web application on a Linux server, covering environment preparation, disabling SELinux, installing dependencies, setting up Apache and MariaDB, cloning the source, adjusting permissions, and completing the web‑based setup.
The article investigates how loss of TCP SYN, SYN‑ACK, or ACK packets during the three‑way handshake affects MySQL client‑server connections, demonstrating retransmission behavior, kernel parameter tuning, and keep‑alive mechanisms through controlled iptables and tcpdump experiments.
This tutorial introduces the Linux stream editor sed, explains its working principle, common usage scenarios, regular expression basics, essential command syntax, address selection methods, and provides practical examples to help readers efficiently perform automated text manipulation tasks.
The article investigates why two MySQL 5.7.32 installations on RedHat 7 show different client character sets—utf8 in the first batch and latin1 in the second—by reviewing MySQL charset settings, OS locale configuration, and providing corrective commands.
This article explains Linux's process memory layout, allocation mechanisms, out‑of‑memory handling, where different types of memory reside, and both manual and automatic memory reclamation techniques, providing practical examples and kernel‑level insights for developers and system engineers.
This guide walks beginners through downloading, installing, and configuring MySQL 8.0.28 on Windows and Linux, covering environment variables, service management, password recovery, user and role creation, and JDBC connection setup with Maven, providing detailed commands, code snippets, and troubleshooting tips for a complete setup.
This guide explains how to install the Go‑based logo‑ls utility as a feature‑rich replacement for the traditional ls command, shows how to test it, configure an alias to make it the default, and where to find further documentation.
This guide compiles 24 practical Docker troubleshooting scenarios—from storage migration and disk space errors to network configuration, NFS mounts, and container management—providing clear problem descriptions, step‑by‑step solutions, and ready‑to‑use command snippets for Linux environments.
Docker Desktop, the integrated Docker IDE, has finally been released for Linux, offering the same experience as on macOS and Windows, while also introducing Docker Extensions, a new SDK, and sparking debate over recent subscription pricing changes that affect enterprise users.
This article explains why the Linux cp command appears to copy a 100 GB file in less than a second by exploring sparse files, the distinction between file size and allocated blocks, inode structure, multi‑level block indexing, and how these concepts enable fast copying of seemingly huge files.
This guide covers step‑by‑step methods to recover forgotten root passwords on various Linux distributions, explains common filesystem directories, lists essential commands, details SUID/SGID/sticky bit usage, shows how to configure static IPs in bridge and NAT modes, set up local yum repositories, manage iptables and firewalld rules, and provides basic shell scripting and hardening tips.
The article explains several destructive Linux commands—including rm -rf, fork bombs, direct disk writes, and hidden shellcode—detailing their effects, providing code examples, and warning readers to understand and test them carefully to avoid irreversible system damage.
This guide explains how to configure Maven profiles and the assembly plugin to create a zip package for a Spring Boot application, then use a reusable shell script to unzip, start, stop, and restart the service on Linux, streamlining deployment across multiple environments.
Nvidia’s release of the open‑source R515 GPU driver for Linux, supporting data‑center and consumer GPUs under a dual GPL/MIT license, marks a pivotal shift that eases integration for AI/ML developers, gamers, and cloud users while fostering community‑driven improvements to driver quality and security.
This article explains how to package a Spring Boot application using Maven profiles and the maven‑assembly‑plugin, generate a zip release, and deploy it on Linux with a reusable shell script that handles unzip, start, stop, and restart operations.
This article examines a real‑world file‑watching failure caused by a JDK bug, explains how Java's WatchService works (including its polling fallback), compares it with Linux's inotify mechanism, and presents practical work‑arounds for reliable configuration reloads in backend services.
This article explains Linux memory metrics VSZ, RSS, and PSS, illustrates them with a roommate analogy, details PageCache and its role in I/O, describes swap behavior and the swappiness setting, and introduces zero‑copy techniques to reduce data copying and context switches.
This article explains the fundamentals of SSH, key‑based authentication, the SSH agent workflow, how SSH agent forwarding operates, how to configure ProxyJump, and the associated security risks along with mitigation techniques.
This article examines whether Linux can serve as a daily‑primary operating system by comparing installation ease, hardware compatibility, user‑interface experience, software ecosystem, gaming support, and maintenance effort against Windows, offering practical advice for different user skill levels.
This article explains the definitions of Linux buffers and cache, how the free command reports them, and demonstrates through experiments that buffers can cache both reads and writes while cache primarily handles page caching for file reads and writes.
Linux kernel version 5.18-rc6 has been released as the weekly candidate, featuring updates to network and RDMA drivers, x86 KVM fixes, wireguard self‑tests, Btrfs patches, and various architecture and core network bug fixes, with the stable 5.18 expected in 2‑3 weeks.
This guide shows how to set up an Ubuntu 16.04 virtual machine on Windows, install QEMU, fetch a modernized Linux 0.11 source tree, and use VSCode Remote‑SSH together with GDB to debug the historic kernel without rebuilding outdated toolchains.
This article provides a comprehensive guide to Linux memory management on x86‑32 systems, covering virtual address spaces, physical address translation, memory zones, user and kernel space layouts, the buddy and slab allocators, malloc/kmalloc/vmalloc mechanisms, and useful commands for inspecting memory usage.
This article explains Linux’s storage I/O stack, defines the five core performance metrics—utilization, saturation, IOPS, throughput, and response time—and demonstrates how to monitor them using tools such as iostat, pidstat, and iotop, with practical command examples.
Learn seven practical uses of the Linux find command—from locating files by name, type, timestamps, size, permissions, and ownership to executing actions like deletion—complete with interview‑style examples and clear code snippets for mastering this essential system tool.
Learn five practical tips to prevent common Bash variable errors—such as avoiding spaces around '=', correctly defining arrays, choosing proper quoting, using $(…) instead of backticks, and steering clear of reserved environment variable names—to write reliable Linux shell scripts.
This article provides a comprehensive guide on configuring and optimizing Zabbix agent monitoring for Linux and Windows, covering agent types, passive and active modes, macro variables, LLD macros, CPU/memory/file‑system metrics, and Windows service, performance counter, and event‑log monitoring.
This article explains how to identify the root causes of Linux network latency—including transmission delays, kernel processing speed, and application handling—by using tools such as hping3, traceroute, wrk, tcpdump, and Wireshark, and offers practical steps to mitigate the delays.
This guide explains how to use the Bash built‑in test command for evaluating numeric, string, and file conditions, shows practical examples with && and || chaining, and demonstrates alternative bracket syntax for robust shell scripting.
This tutorial explains how to create a Python program that uses OpenCV to take a picture with the computer's webcam at startup, checks network connectivity, constructs an email with the photo attached, and automatically sends it, including setup for Linux auto‑start.
This guide walks through downloading, compiling, and installing Nginx from source on Linux, configuring dependencies, creating a systemd service, managing start/stop commands, understanding the directory layout, and setting up basic nginx.conf directives—including worker processes, connections, MIME types, and virtual host server_name patterns.
This guide presents a comprehensive set of Linux server optimization techniques—from kernel I/O scheduling and daemon reduction to filesystem choices, TCP tuning, and essential performance commands—helping system administrators boost efficiency, security, and reliability across diverse workloads.
This article provides a comprehensive overview of Podman, an open‑source, daemon‑less container runtime, compares it with Docker, explains key architectural differences, and offers detailed instructions on installation, configuration, common commands, rootless usage, volume handling, and migration aliases.
This article compares Podman and Docker, detailing their architectures, root privileges, security, integration with Kubernetes, image building tools, and how they can be used together, helping developers choose the appropriate container runtime for their projects.
This article explains how to use Maven profiles and the maven‑assembly‑plugin to create environment‑specific Spring Boot zip packages, configure the accompanying assembly.xml, and deploy them on Linux with a custom shenniu_publish.sh script that supports unzip, start, stop and restart operations.
This article provides an in‑depth comparison of Podman and Docker, covering their architectures, root‑less operation, security, integration with Kubernetes, support for Swarm/Compose, and practical guidance on when to choose or combine each container solution.
This article provides a step‑by‑step tutorial on setting up Prometheus and Grafana for 24/7 monitoring of Linux servers and MySQL databases, covering installation, configuration, data visualization, alerting with onealert, and common troubleshooting tips for reliable operations.
This article walks through creating a Linux packet sniffer that bypasses libpcap, explains PF_PACKET raw sockets, shows how to bind to a specific interface, enable promiscuous mode, attach a BPF filter compiled with tcpdump, and parse Ethernet and IP headers in a continuous receive loop.
The article walks through creating a lightweight, extensible Node.js command‑line utility without third‑party libraries, covering the command‑pattern design, implementation of split, upper, and word‑count commands, dynamic command loading, and best practices for modular, maintainable CLI development on Linux.
Microsoft researchers uncovered the Nimbuspwn vulnerability in systemd’s networkd-dispatcher, detailing how directory‑traversal, symlink‑race, and TOCTOU flaws let attackers replace root‑owned scripts, achieve privilege escalation, and why coordinated patching across hundreds of Linux distributions is critical.
Ubuntu 22.04 LTS, codenamed Jammy Jellyfish, introduces five distinctive capabilities—including optimized data‑driven workloads, enhanced Active Directory integration, a real‑time kernel option, updated packages and drivers, and performance boosts—that together position it as arguably the strongest long‑term support Ubuntu version to date.
This article walks through generating a heavy‑load MySQL workload, using top, iostat, and iotop to pinpoint high disk I/O, mapping OS thread IDs back to MySQL sessions, and safely killing the offending query to relieve pressure.
This guide explains how to use the Linux sleep and wait commands for pausing execution, specifying time units, handling sub‑second intervals, running periodic tasks, and synchronizing background processes, complete with practical Bash examples and detailed explanations.
Learn how to install the pinfo tool across major Linux, BSD, and macOS distributions and use it to view Texinfo documentation with syntax‑highlighted colors, including command examples, navigation shortcuts, and alias configuration for a richer command‑line experience.
This guide explains how to create and manage Bash aliases, view existing shortcuts, and replace simple aliases with parameter‑supporting Bash functions, providing practical examples and code snippets for Linux and macOS command‑line efficiency, especially in Kubernetes workflows.
This guide provides a step‑by‑step tutorial on Nginx, covering its overview, single‑instance installation, reverse proxy setup, load‑balancing configuration, static‑dynamic separation, high‑availability clustering with keepalived, detailed configuration directives, and performance considerations, complete with command‑line examples and code snippets.
This article explains how excessive Linux CPU context switches affect system performance and shows step‑by‑step how to monitor and analyze them using vmstat, pidstat, and sysbench, including interpreting voluntary versus involuntary switches and interrupt statistics.
This article explains several Linux commands—such as rm -rf, fork bombs, direct writes to block devices, and malicious script execution—that can irreversibly damage systems, detailing their effects, typical usage examples, and essential precautions to avoid catastrophic data loss.
This guide walks through downloading DTLE, generating a self‑signed SSL certificate, configuring Nomad with the certificate and key, starting the DTLE services, and verifying HTTPS access to securely protect database credentials during data transfer.
The article introduces the bat command as an enhanced, syntax‑highlighting and automatically paginated alternative to cat, explains its key features such as Git integration and non‑printable‑character display, provides installation and usage instructions on Linux, and shows how to customize its themes.
This article explains how Linux creates the illusion of multitasking by rapidly swapping CPU registers and program counters, details the three types of context switches—process, thread, and interrupt—and shows why excessive switching can significantly degrade system performance.
This guide walks through installing GitLab on a CentOS server, configuring its external URL, setting up admin credentials, performing basic GitLab operations such as disabling auto‑registration, creating projects, configuring SSH keys, testing repository cloning, and configuring webhooks and backup management.
This article explains the key Linux disk performance indicators—utilization, saturation, IOPS, throughput, and response time—and shows how to monitor them using tools such as iostat, pidstat, and iotop, including practical command examples and interpretation tips.
This guide shows how to install and run a collection of classic Linux terminal games—including Bastet (a Tetris clone), Pacman4Console, nSnake, 2048, Nudoku, Moon‑Buggy, Ninvaders, Ascii‑Patrol, Greed, and BSD Games—on Debian/Ubuntu or Fedora/RHEL/CentOS using simple package commands, providing a fun way to learn the Linux command line.
Meituan Search solves costly multi‑language maintenance by building a core C++ library, wrapping it with a C interface, and exposing the functions to Python via ctypes and to Java via JNI or JNA, enabling shared logic, easier packaging, and lower latency on Linux.
This article provides a step‑by‑step tutorial on what Anaconda and Conda are, how to install Anaconda on Linux, manage Python environments, handle packages, configure mirror sources, use Miniconda, the graphical UI, and run Jupyter Notebook, while also discussing their pros and cons.
This guide walks you through installing the open‑source NginxConfig visual tool, configuring Node.js, generating Nginx configuration files for static and dynamic proxies, and deploying them on a Linux server to simplify backend operations.
This guide explains how to install and run the beta Upgrade Tool to safely upgrade Linux Mint Debian Edition (LMDE) 4 to LMDE 5, including required package commands, graphical launch steps, post‑upgrade cleanup, and important precautions.
Discover a curated list of entertaining Linux commands—like cmatrix, xcowsay, sl, aafire, and more—complete with installation steps, usage examples, and visual demos that turn your terminal into a playful showcase.
This comprehensive guide walks you through Linux server hardening—covering account and login security, remote access safeguards, file system protection, rootkit detection tools, and step‑by‑step incident response—to help you prevent breaches and recover swiftly if an attack occurs.
This guide walks through the complete process of adding a Jenkins agent, from creating the node in the Jenkins UI and installing Java and Git on the remote machine to copying SSH keys, verifying connectivity, and testing the agent’s operation.
The article details a step‑by‑step investigation of why HTTP request latency increased after moving a Go‑based service to new hardware, focusing on DNS resolution delays, the role of DNSmasq, Go's resolver implementation, and the experiments that led to fixing the issue.
The three‑day openEuler Developer Day 2022 showcased the release of openEuler 22.03 LTS, a new ecosystem service platform, partner commercial plans, extensive SIG sessions, and a series of technical demos highlighting server, cloud, edge, and embedded scenarios across the open‑source community.
This article explains why Linux treats every thread as a process, describes the core kernel data structures task_struct, thread_info and the kernel stack, details the clone‑based creation path, and clarifies virtual address spaces, page tables, and the differences between user processes and kernel threads.
Learn how to configure and read Nginx access and error logs, including defining log formats, setting file locations, customizing log levels, parsing log fields, and using command‑line tools to monitor logs in real time, with practical examples and best‑practice recommendations.
This article explains the structure of Linux Ext2/3/4 file systems, the role of superblocks and block groups, compares hardware and software RAID, and introduces LVM for flexible storage management, highlighting both benefits and risks.
This guide explains step‑by‑step how to use built‑in command‑line tools on Windows, Linux, and macOS to list previously connected Wi‑Fi networks and reveal their stored passwords, allowing you to recover forgotten network credentials across all major operating systems.
This article compiles a comprehensive collection of practical Bash scripts—from a number‑guessing game and remote IP counting to system monitoring, user management, and one‑click LNMP deployment—providing Linux engineers with ready‑to‑use tools that boost productivity and automate routine tasks.
This article presents a systematic performance comparison of several Linux file‑transfer utilities—including scp, ftp, sftp, rsync, tftp, nc, and a Python SimpleHTTPServer—by measuring transfer times for a 50 GB single file and 51 GB spread across 51 200 one‑megabyte files, and discusses each tool’s speed, compression, encryption, and typical use cases.
This comprehensive guide walks developers through Nginx fundamentals, key features, installation on CentOS, essential commands, core configuration blocks, directive details, variable usage, upstream and proxy_pass setup, reverse proxy, load balancing strategies, caching, HTTPS, CORS, gzip compression, and the internal architecture, enabling you to confidently deploy and manage Nginx in production environments.
This tutorial walks through setting up a three‑host Linux environment, using Docker, sar, hping3, tcpdump and iptables to reproduce a SYN‑Flood DDoS attack, analyze its impact, and apply kernel and firewall tweaks to mitigate the attack.
This comprehensive guide explains Nginx's role as a high‑performance web and reverse‑proxy server, details its installation packages and step‑by‑step build process, breaks down the main nginx.conf sections, and demonstrates practical configurations for reverse proxy, load balancing, static‑dynamic separation, worker tuning, and high‑availability clustering.
This guide walks through configuring an NFS server, installing required utilities, creating a dedicated namespace, installing Helm, and deploying the nfs-client-provisioner chart to provide dynamic NFS storage for workloads in a Kubernetes cluster.
The article introduces the Python‑based tool “thefuck”, explains its purpose of automatically correcting mistyped shell commands, demonstrates common use cases, details installation steps across macOS, Ubuntu and other systems, shows how to configure it, and outlines the underlying rule‑based correction mechanisms.
This article explains Nginx's multi‑process design, detailing how the master process handles socket binding and listening while each worker creates its own epoll instance, registers events, and processes connections through a well‑structured event loop with code examples from the source tree.
This guide compiles a comprehensive set of Linux commands—using awk, grep, netstat, and other tools—to help you count unique IPs, rank page visits, filter bots, monitor connection states, calculate bandwidth, and identify high‑traffic or error‑prone resources from Apache or Nginx logs.
This article provides a detailed tutorial on installing Caddy on CentOS and Docker, configuring its powerful Caddyfile syntax, enabling HTTPS, reverse and forward proxy, gzip compression, address rewriting, and directory routing, demonstrating how Caddy can replace Nginx for modern web hosting.
This article explains how the Linux kernel’s kswapd thread is created, when it is awakened, and the detailed steps it follows—including LRU management, zone migration, balance_pgdat, and shrink functions—to reclaim memory efficiently on memory‑constrained devices.
This article introduces the ELK stack components, explains why centralized logging is essential, outlines core log‑system features, compares three ELK architectures, provides step‑by‑step installation and configuration for Filebeat, Logstash, Elasticsearch and Kibana, and demonstrates a complete pipeline using Kafka with code examples and diagrams.
This article provides a step‑by‑step guide to installing RedisInsight, configuring its environment variables, launching the service on Linux, deploying it with Kubernetes, and using its graphical interface to monitor and manage Redis clusters, keys, and memory.
