This article explains how operating systems manage diverse I/O devices through device controllers, registers, drivers, DMA, and Linux’s generic block layer, and walks through the complete sequence that occurs—from a keyboard press to the character appearing on the screen.
This article explains how Linux system calls work, compares their overhead to regular function calls, and details the three implementation methods—software interrupts, fast syscall instructions, and the virtual dynamic shared object (vDSO)—including their performance trade‑offs and practical usage.
This guide walks through installing the Hack TrueType font on Ubuntu 18.04, covering downloading from GitHub, extracting the archive, creating a local fonts directory, moving files, rebuilding the font cache, verifying the installation, and optionally removing the font, with all commands provided.
This guide walks through the complete process of setting up a fault‑tolerant RocketMQ cluster on two Linux servers, covering environment preparation, Java installation, NameServer and Broker deployment, configuration of master‑slave modes, startup commands, troubleshooting, port opening, verification, and optional console installation.
This guide walks you through accessing the GRUB menu, editing boot parameters, gaining a root shell, and safely resetting the root password on Ubuntu 18.04 LTS or 20.04 LTS without needing the original credentials.
This guide walks through verifying the existing Nginx 1.16.1 process, compiling and configuring Nginx 1.18.0 with identical options, performing a zero‑downtime binary replacement, and handling rollback procedures using signals and process management commands on a Linux server.
This article shares the author's personal experience transitioning from Windows to Linux, discusses motivations like learning and freedom, outlines Linux's advantages and drawbacks, and provides detailed troubleshooting steps for common issues on Debian/Ubuntu such as graphics, Wi‑Fi, IDE rendering, and input method bugs.
This guide shows a quick user‑space technique to conceal a Linux process by overwriting its PID with an unused value using a short SystemTap script, includes the exact code, execution steps, detection method, and a brief explanation of why it works.
This article shares a two‑year personal experience with the Deepin Linux distribution, covering its graphical desktop, daily development tools, social communication apps, ability to run Android applications, and a detailed list of advantages that make Linux a viable alternative to Windows for many users.
The article explains how Position Independent Code (PIC) enables code to run at any address using GOT and PLT tricks, how Position Independent Executables (PIE) extend this to whole binaries, and how Linux’s Address Space Layout Randomization (ASLR) leverages PIE to fully randomize process memory, making exploitation significantly harder.
This guide explains why printf outperforms echo in shell scripts, details its syntax, lists essential escape characters and conversion specifiers, and provides multiple practical examples—including numeric bases, floating‑point formatting, tabular output, and colored alignment—to help you format command‑line output precisely.
This article shares a personal experience of using Linux as a daily development platform, covering its graphical desktop, supported development tools, communication apps, ability to run Android applications, and the many efficiency, freedom, and aesthetic advantages that make it a viable Windows alternative.
This step‑by‑step guide shows how to enable security groups, install the BT control panel, configure firewall rules, deploy JDK and Tomcat, and install Docker on a Linux server, including all required commands and troubleshooting tips.
This guide explains why dual‑booting is being replaced by WSL 2, describes its architecture and performance benefits, and provides step‑by‑step instructions for installing Ubuntu 20.04, configuring WSL 2, and setting up VS Code, Docker, Kubernetes, and the new Windows Terminal for a powerful developer workstation.
This comprehensive guide walks through Linux's core components—including the kernel, shell, and file system—explaining memory and process management, VFS architecture, partition types, mounting procedures, common commands, and optimization tips, all illustrated with diagrams and practical examples.
The article shares a personal experience of using Linux (especially the Deepin distribution) for daily work, development, communication, and multimedia, comparing its advantages over Windows and showing how it can serve as a viable, efficient, and free alternative.
This article explains the distinction between Linux Buffers and Cache, how they appear in the free command, their representation in /proc/meminfo, and demonstrates practical experiments using vmstat and dd to observe their behavior during read and write operations, concluding with clear usage guidelines.
This guide shows how to compile Flameshot on Ubuntu 16.04, integrate the qxtglobalshortcut5 library, register a custom global shortcut (e.g., Ctrl+F5), and use the enhanced tool while noting remaining limitations such as focus‑loss windows and input‑method support.
This guide walks you through a step‑by‑step method for diagnosing a sluggish production server, covering overall system status with top, CPU usage via vmstat, memory with free, disk space with df, disk I/O using iostat, and network I/O using sar, so you can confidently answer interview questions.
Bashtop is a visually appealing, terminal‑based Linux resource monitor that displays CPU, memory, processes and network usage, and this guide walks you through its prerequisites, manual and package‑manager installations across major distributions, configuration options, and basic usage commands.
This step-by-step tutorial explains how to prepare a CentOS environment, install Java and Maven, clone the Ratel source code, build the project, launch the command-line Dou Dizhu client, and play the game with various modes, providing all necessary commands and screenshots.
This guide introduces five Linux command‑line calculators—bc, calc, expr, gcalccmd, and qalc—explaining how to install them on various distributions, use their interactive and non‑interactive modes, and perform common arithmetic, scientific, and unit‑conversion tasks.
This article presents a curated list of the ten most popular Linux distributions used for penetration testing and ethical hacking, detailing each distro's base system, key features, toolsets, and where to download them, helping security professionals choose the right platform for their needs.
The article explains Linux page cache fundamentals, shows how to inspect and reclaim cache, and provides detailed tuning of vm.dirty_* and vm.swappiness parameters to smooth Kafka write traffic, reduce I/O spikes, and improve overall performance, illustrated with before‑and‑after benchmarks.
This guide explains the Linux ps command, its basic options, output formats, and practical examples for listing all processes, filtering by user, CPU or memory usage, sorting, displaying threads, tree view, security information, root‑owned processes, and combining ps with watch for near‑real‑time monitoring.
This step‑by‑step guide shows how to set up a Discuz! forum on a Huawei Cloud CentOS 7.6 server, covering cloud login, security group configuration, installation of Apache, PHP, MariaDB, downloading and deploying Discuz! source, and final web‑based installation.
This article explains the five I/O models—blocking, non‑blocking, I/O multiplexing, signal‑driven, and asynchronous—detailing their operation, typical applications, advantages, and drawbacks within the Linux/UNIX networking environment, and compares synchronous versus asynchronous I/O concepts.
This guide explains how to restore accidentally deleted files on Linux by handling two scenarios—when the deleting process still holds an open file descriptor and when it has terminated—using lsof, /proc tricks, and the extundelete utility with step‑by‑step commands.
This guide walks through installing Erlang and RabbitMQ, configuring a mirrored RabbitMQ cluster, setting up HAProxy load balancing, and using Keepalived for automatic failover, providing a complete high‑availability solution for RabbitMQ on Linux.
This tutorial walks you through installing Zabbix on CentOS 7, covering prerequisite disabling of SELinux and firewalls, adding repositories, installing server, web, and database components, configuring files, securing MariaDB, starting services, and completing the web‑based setup with language customization.
This guide explains how to use Linux non‑blocking socket APIs (select, poll, epoll) and the OpenResty platform (Nginx + LuaJIT) to create scalable, high‑concurrency web services, covering architecture, caching strategies, and step‑by‑step installation and configuration.
This guide walks you through setting up a fault‑tolerant RocketMQ cluster on two CentOS 7 machines, covering deployment options, environment preparation, Java installation, NameServer and Broker configuration, startup procedures, troubleshooting, and optional console installation.
This tutorial provides a comprehensive, step-by-step procedure for setting up a log‑collection pipeline using Filebeat, Kafka, Zookeeper, Logstash, Elasticsearch, and Kibana across multiple servers, covering hardware preparation, system tuning, software installation, configuration files, and verification commands.
This article provides a comprehensive introduction to Docker, covering its underlying technology, reasons for adoption, step‑by‑step installation on CentOS, essential image and container commands, detailed Dockerfile instructions, and practical examples for building and running a Spring Boot application.
This guide introduces several handy Linux command-line tricks, including the 'z' shortcut for rapid directory navigation, a feature‑rich Vim configuration, customizing MySQL prompts, reliable methods to display system version details, and concise commands for checking disk usage, helping users streamline their workflow.
This guide explains Linux's memory architecture, how virtual memory (swap) works, and provides step‑by‑step commands to adjust swappiness, release page caches, and safely free swap space, helping you optimize system performance and avoid memory‑related issues.
This article examines the keep‑alive mechanism at both the HTTP and TCP layers, explains how Nginx parses and processes the Connection header, dissects Linux kernel socket options and libuv implementation, and shows how to configure and debug keep‑alive to release idle connections efficiently.
This guide explains how to install, start, name, detach, reattach, nest, switch between, and close GNU Screen sessions on Linux, providing concrete commands and key shortcuts to keep long‑running tasks alive even when network connections drop.
This guide explains how to use the Linux ps command to inspect and control processes, covering basic usage, common options, output formatting, filtering by user, CPU or memory usage, displaying process trees, security information, and real‑time monitoring with watch.
This guide explains how to analyze a sluggish production server by examining overall system metrics, CPU usage, memory, swap, disk space, and I/O using common Linux commands such as top, vmstat, free, df, iostat, and sar, with practical interpretation tips for each output field.
This article introduces four widely used Linux monitoring tools—iotop, htop, IPTraf, and Monit—explaining their features, usage scenarios, and how they help operations engineers diagnose performance issues without a GUI, including real‑time I/O tracking, visual CPU/memory graphs, network traffic analysis, and flexible alerting.
Explore the lineage from the 1969 birth of UNIX through the creation of Linux, the emergence of Apple's iOS, and the development of Android, highlighting key milestones, contributors, and how these systems interconnect as the foundational kernels of today’s major platforms.
This article walks through the design and implementation of a tiny Linux filesystem called TinyFS, explaining the VFS layers, required POSIX interfaces, data structures, core kernel code, usage steps, current limitations, and a roadmap for extending it with proper superblocks, concurrency, and page‑cache integration.
This article explains the role of virtual memory in Linux, covering the difference between physical and virtual memory, how swapping frees RAM, the two implementation methods—swap partitions and swap files—along with swappiness tuning and the performance benefits they provide.
This guide walks through installing InfluxDB and Grafana on CentOS, configuring InfluxDB for Flink metrics storage, creating databases and retention policies, integrating the Flink InfluxDB reporter, and building Grafana dashboards to visualize real‑time Flink job metrics.
This guide explains how to view and modify the Bash prompt using the PS1 variable, add time stamps, apply ANSI color codes, and make the changes permanent by editing .bashrc or global configuration files, with step‑by‑step commands and examples.
This article explains what MySQL binlog is, how to enable row‑based logging, and provides step‑by‑step Linux commands using mysqlbinlog and grep to extract historical SQL statements such as DELETE operations for troubleshooting and debugging purposes.
This tutorial lists twelve practical Ubuntu keyboard shortcuts—from opening the search bar with the Super key to creating custom shortcuts—explaining how each shortcut works and how it can speed up everyday tasks and improve overall workflow efficiency.
This guide walks you through checking current disk usage, adding a new disk, creating an LVM partition, extending the volume group and logical volume, resizing the filesystem, and verifying the expansion on a CentOS 7 system to resolve disk‑space shortages.
This guide walks you through selecting a low‑cost Raspberry Pi Zero W, flashing Raspbian Stretch Lite, configuring SSH and Wi‑Fi, optimizing the system, installing Nginx, and exposing the web service to the internet using ngrok, providing a compact, fully functional mini web server.
This guide explains how to restore mistakenly removed Linux files by first checking if the deleting process still holds the file descriptor using lsof, then copying the open file from /proc, and finally using the extundelete tool when the process has already terminated.
This article explains how Linux organizes a process's address space into text, data, and stack segments, describes virtual memory concepts such as paging, page tables, and page faults, and details the kernel's allocation, deallocation, and memory‑mapping mechanisms including brk, mmap, and the buddy allocator.
This article introduces seven entertaining command‑line games for Linux, ranging from classic rogue‑likes like NetHack and Dwarf Fortress to text‑adventure interpreters, BSD game collections, a survival rogue‑like, the 2048 puzzle, and a multiplayer Snake, all runnable directly in a terminal.
This guide walks through installing and configuring a Ceph distributed storage cluster, covering node preparation, hostname and hosts setup, password‑less SSH, required packages, firewall handling, time sync, ceph‑deploy installation, monitor creation, OSD configuration, pool and RBD creation, verification, and common troubleshooting steps.
This article traces the early emergence of Chinese Linux‑based operating systems, analyzes the reasons for their limited market impact, outlines the recent ecosystem improvements and policy support, and reviews key players, CPU developments, and the unified strategy behind modern domestic OS solutions such as UOS and Kylin.
This guide explains how to use systemctl and journalctl on CentOS 7 to list services that failed to start, check individual service status, interpret error messages, and filter logs for troubleshooting, providing concrete command examples and output analysis.
This tutorial explains why a changing desktop IP can disrupt mouse‑sharing tools and walks you through checking the current network settings, recording the IPv4 address, gateway, mask and DNS, and then configuring a static IP (e.g., 192.168.0.210) in Ubuntu’s Network settings, ending with applying the changes and rebooting.
This comprehensive guide introduces Ansible, covering its core concepts, features, installation, inventory setup, ad‑hoc commands, module usage, playbook creation, handlers, and role-based organization to enable efficient, agent‑less automation across diverse Linux and network environments.
This article explains the concepts of processes, their identifiers, the fork system call, and the differences between orphan and zombie processes, providing code examples, output analysis, and practical ways to handle each situation on Unix‑like systems.
The article explains the semantics of the Linux kill command, why using kill -9 for abrupt termination is risky, how to prefer SIGTERM (kill -15) for graceful shutdowns, shows Java shutdown‑hook usage, and provides a shell script that automates safe process termination.
This article provides a comprehensive guide to gh-ost, the GitHub‑released online MySQL schema migration tool, covering its design principles, three migration modes, download and RPM installation, common command‑line options, interactive socket commands, and a step‑by‑step example of altering a column type while monitoring progress and performing a safe cut‑over.
A real‑world incident showed that a 0% CPU idle rate can mask severe disk IO wait, leading to thread exhaustion in a SpringBoot order service, and the article explains how IO, DMA, Java thread states, and various Linux network IO models interact while offering practical mitigation tactics.
This article introduces SSH, explains its encryption fundamentals, demonstrates basic usage, remote login, various port forwarding techniques, and remote command execution, while also covering common pitfalls and security considerations, providing step‑by‑step examples and practical commands for Linux environments.
This article explains how to enable Linux CGroup support in Hadoop Yarn NodeManager to limit container CPU usage, detailing required configuration properties, hierarchy setup, CPU limit parameters, and a critical kernel version caveat.
This guide outlines key Linux utilities for inspecting binaries during compilation (nm, strings, strip, readelf, objdump, addr2line) and for runtime debugging and profiling (gdb, ldd, strace, ltrace, time, gprof, valgrind, mtrace, oprofile), plus an overview of the proc filesystem and common system logs.
This article explains Linux's zero‑copy techniques—mmap, sendfile, and splice—detailing how they reduce data copies between user and kernel space, improve I/O efficiency, handle edge cases like SIGBUS, and leverage DMA to minimize CPU overhead in server file transfers.
This guide explains Linux redirection fundamentals, covering stdin, stdout, and stderr streams, how to view their device files, and practical examples of redirecting output, input, error messages, and using /dev/null, Here‑doc, and Here‑string to simplify command‑line workflows.
This guide explains how to use the Linux ps and grep commands to identify zombie processes, interpret their status fields, and safely terminate them with kill -HUP, including steps to verify removal and alternative methods using top.
This guide explains how to install the HardInfo utility on Linux, use its graphical interface to view detailed hardware components such as CPU, RAM, motherboard, GPU, storage, network, and run built‑in benchmarks, plus how to generate a comprehensive hardware report.
This article introduces several Linux interprocess communication mechanisms—including pipes, message queues, shared memory, semaphores, signals, and sockets—explaining their principles, advantages, drawbacks, and typical usage scenarios for developers preparing for system‑level programming or interviews.
This article explains why traditional read/write file serving incurs multiple data copies and context switches, then introduces mmap, sendfile, and splice as zero‑copy methods that reduce CPU load, discuss their usage, limitations, and practical pitfalls for high‑performance Linux servers.
This article provides a concise yet comprehensive guide to essential Linux networking tools—including netstat, ss, sar, iftop, and tcpdump—explaining how to monitor connections, analyze traffic, troubleshoot TIME_WAIT and CLOSE_WAIT issues, and tune kernel parameters for high‑concurrency servers.
Learn how the dmesg utility reads the Linux kernel’s ring buffer, displays boot and runtime messages, and how to use its many options—such as filtering, formatting timestamps, clearing the buffer, and handling permission restrictions—to troubleshoot hardware and kernel issues effectively.
This article walks through common Linux memory inspection commands, explains the meaning of the buff/cache field, and then dives into MySQL join types, join algorithms, buffer settings, and performance‑tuning tips, all presented as a simulated interview with promotional side notes.
When using sudo, Linux resets the environment, causing custom variables to disappear; this guide explains why, shows the relevant lines in /etc/sudoers, and presents three practical methods—including sudo -E, editing env_keep and secure_path, and creating aliases—to retain needed variables.
This guide walks through converting a spare ASUS laptop into a home‑hosted cloud server by installing Debian 10, configuring the Baota control panel, setting up router NAT and static IP, automating DDNS with an open‑source script, and measuring power and bandwidth results.
This guide details the complete process of installing Jenkins Server, covering prerequisite Java installation, multiple deployment methods—including Tomcat, CentOS, macOS, Docker, Kubernetes, and Windows—followed by essential post‑installation configuration and resource links.
This guide walks through what Squid is, its traditional and transparent proxy modes, step‑by‑step installation, configuration of cache directories, service scripts, temporary and permanent proxy settings on Linux, and notes on using Squid as a unified outbound gateway.
This article explains why traditional password and key logins are vulnerable, introduces SSH certificate authentication using a Certificate Authority, and provides detailed commands and procedures for generating CA keys, issuing server and user certificates, configuring both server and client, and revoking certificates when needed.
This guide explains how to install and use the Linux command‑line tools iftop and nethogs for real‑time network traffic monitoring, covering installation commands, interface selection, output interpretation, shortcut keys, and advanced options to help troubleshoot slow or blocked network connections.
This article provides a comprehensive overview of Linux fundamentals, covering process and thread concepts, various inter‑process communication mechanisms, essential system calls, process descriptors, scheduling algorithms such as O(1) and CFS, synchronization primitives, and the operating system boot sequence.
This guide explains the Linux cut command, covering its basic syntax, essential options such as field, delimiter, byte and character extraction, and advanced features like complement and custom output delimiters, with step‑by‑step examples and notes on limitations.
This article reviews six contemporary Linux command‑line utilities—ncdu, htop, tldr, jq, fd, and other alternatives—that improve usability, speed, and functionality compared with traditional tools like du, top, man, grep, and find, providing installation commands and usage examples.
This comprehensive guide covers fundamental Linux commands such as ls and cat, user and group management, package handling with RPM and yum, process monitoring tools, file searching utilities, scheduled task creation with at and crontab, and automating interactions using Expect, providing clear examples and code snippets for each topic.
This article compares the three I/O multiplexing mechanisms—select, poll, and epoll—by analyzing their time complexities, limitations, trigger modes, performance characteristics, and implementation details, helping developers choose the most suitable method for different Linux networking scenarios.
This article outlines common intrusion signs on CentOS 6.9 systems, explains how to examine logs, user files, login records, network traffic, and demonstrates using lsof and /proc to recover deleted security logs, providing practical commands for Linux security engineers.
This article explains why operating system and driver defects cause system hangs and reboots, introduces the methodology of memory dump analysis—including deadlock and exception techniques—and walks through a real Linux kernel panic case to illustrate how to trace, diagnose, and remediate such crashes.
This article provides a comprehensive overview of Linux fundamentals, covering process and thread concepts, the fork and exec system calls, various inter‑process communication mechanisms, memory layout, scheduling algorithms such as O(1) and CFS, synchronization primitives, and the boot sequence, all illustrated with code snippets and diagrams.
This article walks through a real‑world Oracle 19c RAC deployment on Red Hat 7.6, detailing the root.sh failure caused by a missing IPv6 ::1 entry, patch installation errors due to file permission problems, and step‑by‑step IPv6 network configuration to get the database fully operational.
This article explains how to modify systemd unit files or use systemctl commands to set resource isolation parameters such as CPUQuota and MemoryLimit, demonstrates the changes with a MySQL CPU‑usage experiment, and describes the underlying cgroup and systemd mechanisms on Linux 7.
This tutorial explains the Linux dmesg command, covering its purpose for accessing kernel ring‑buffer messages, basic usage, common options for formatting, filtering by facility or level, permission handling, and techniques for viewing, paging, grepping, saving, and clearing kernel logs.
This tutorial shows Linux system administrators and DevOps engineers how to create a fully customizable, distributed monitoring dashboard by installing and configuring Prometheus, Pushgateway, and Grafana, writing a Bash script to push process metrics, and visualizing CPU and memory usage with Grafana panels and PromQL queries.
This guide shows how to install and use nload, iftop, and sar for live network bandwidth monitoring on Linux, explains their key parameters, and provides two shell scripts that calculate per‑second inbound and outbound traffic from /proc/net/dev.
This article explains why massive TIME_WAIT TCP connections appear under high concurrency, the impact on services, and practical methods—such as adjusting socket reuse and reducing TIME_WAIT duration—to prevent new connection failures.
This guide explains why the standard cat command lacks syntax highlighting, introduces the ccat utility that adds colored output for many programming languages, and provides step‑by‑step installation instructions for Arch and other Linux distributions, along with practical usage examples and troubleshooting tips.
Linux developers, led by Linus Torvalds, have approved a proposal to replace racially sensitive terms like master/slave and blacklist/whitelist with neutral alternatives, reflecting a broader industry move toward inclusive language in code and documentation.
This guide walks you through Linux fundamentals, installation methods, essential commands, directory and file operations, networking, firewall, package management, MySQL and Tomcat deployment, as well as user, group and scheduled‑task administration, providing practical examples and code snippets for each step.
This article compares the three I/O multiplexing mechanisms—select, poll, and epoll—detailing their time‑complexities, limitations, implementation details, trigger modes, and performance trade‑offs to help developers choose the most suitable method for different Linux networking scenarios.
This article explains how Linux signals like SIGHUP affect background processes, why using nohup (or similar tools) prevents termination when the controlling terminal exits, and provides practical examples and code for handling signals directly.
This tutorial provides a comprehensive Docker quick‑start for Linux, covering installation, essential commands, container lifecycle, image management, and step‑by‑step containerization of a frontend project with Dockerfile creation, image building, container deployment, registry push, and common troubleshooting FAQs.
