This guide presents 35 practical Linux find command examples covering file and directory name searches, case‑insensitive matching, permission‑based queries, size and time filters, as well as combined find‑and‑delete operations, helping users efficiently locate and manage files on Unix‑like systems.
This article explains the fundamentals of the ping utility, detailing its basic output fields, interpreting bytes, time, and TTL values, and demonstrates advanced switches such as -t, -a, -n, -l, -r, as well as batch ping techniques for network troubleshooting.
This guide explains Linux file I/O fundamentals, covering file concepts, standard streams, system calls like open and dup2, file descriptor allocation, redirection, the FILE structure, inode layout, hard and soft links, and the creation and usage of static and dynamic libraries, all illustrated with code snippets and diagrams.
This article walks through the complete process of creating a highly available MySQL master‑master cluster using Docker containers, MySQL replication, and Keepalived for automatic health checks, virtual IP failover, and seamless traffic switching, while also sharing common pitfalls and their solutions.
This article provides a detailed analysis of Linux kernel spinlocks, focusing on the evolution from ticket‑based locks to the modern queued spinlock (qspinlock), explaining its code hierarchy, data structures, state machine, and the acquisition/release algorithms with accompanying diagrams.
Ubuntu 22.04 LTS enables systemd‑oomd by default, but many users report that it unexpectedly kills applications like Firefox, Chrome, and VS Code even without visible memory pressure; Canonical explains the termination conditions, highlights the swap‑size issue, and outlines planned fixes for the upcoming 22.04.1 release.
This guide explains how C/C++ source code is transformed into a runnable binary on Linux by walking through the four stages of preprocessing, compilation, assembly, and linking, detailing GCC and Binutils utilities, command‑line examples, and ELF file inspection techniques.
This article provides a comprehensive walkthrough of Linux kernel memory management, covering process address space layout, memory allocation mechanisms, OOM selection criteria, where allocated memory resides, and both manual and automatic memory reclamation techniques, complete with code examples and diagrams.
This article walks through setting up a high‑availability MySQL environment using master‑master replication and Keepalived on two Ubuntu servers, covering architecture design, Docker container preparation, MySQL configuration, Keepalived installation, failover testing, and troubleshooting common issues.
Linus Torvalds announced at the Linux Foundation Open Source Summit that Rust may be merged into the Linux kernel as early as the next release cycle, outlining a cautious yet stable development approach and highlighting community and industry support for the language.
OpenCloudOS, China’s first fully domestic server operating system, has transitioned from a mere open‑source user to a leading contributor, launching its L1 source community and L3 full‑package version, expanding ecosystem partnerships, and outlining a roadmap that promises future server, desktop, embedded, and edge OS releases.
This guide details how to set up Redis Sentinel for high‑availability in a master‑slave architecture, covering configuration file creation, essential sentinel parameters, starting Redis and Sentinel instances, and verifying operation via log inspection.
This guide explains what the Linux tee command does, how it’s installed, its basic syntax and options, and provides practical examples—including writing output to files, appending data, handling multiple files, piping to other commands, ignoring interrupts, hiding output, and using sudo—so readers can efficiently capture and process command‑line output.
A concise cheat‑sheet of frequently used Linux commands covering file searching, bulk moving, log cleanup, directory checks, text substitution with sed, network packet capture, firewall rules, and log analysis to boost sysadmin productivity.
This article compiles a comprehensive list of over a hundred Linux, networking, load‑balancing, database, caching, monitoring, container and cloud‑native interview questions, providing candidates with essential knowledge to ace system‑administration and DevOps job interviews.
This article provides a comprehensive analysis of the Linux USB core architecture, detailing the device and interface layers, the struct usb_device model, USB Request Block handling, hub driver operations, EHCI host controller scheduling, and a complete example of a USB mouse client driver, complete with code snippets.
This article provides a comprehensive guide to iptables, explaining its hierarchical structure of tables, chains, and rules, detailing the built‑in tables (filter, nat, mangle, raw) and their chains, describing rule syntax and target actions, and offering practical command examples for listing, flushing, saving, setting default policies, and configuring SSH, HTTP, NAT, and IP‑based restrictions.
This guide explains how to install the ngx_http_geoip2 module, upgrade Nginx, download the MaxMind GeoIP2 database, configure geoip2 directives and map rules, and finally block non‑Chinese IP addresses by returning a 404 response.
This article compiles a comprehensive set of Linux shell scripts and command snippets covering zombie‑process detection, MySQL and directory backups, network ping scans, disk I/O diagnostics, performance monitoring, process management, Java dumps, common tool and library installations, system health checks, and advanced sed techniques, providing practical automation for system administrators.
The article lists several dangerous Linux commands—including rm -rf, fork bomb, direct writes to block devices, and disguised payloads—explaining their syntax, destructive effects, and the importance of understanding and avoiding their execution to prevent irreversible system damage.
The May 2022 Steam Hardware & Software Survey shows Linux's overall share slipping slightly to 1.12% while Windows dominates at 96.68%, and reveals Arch Linux surpassing Ubuntu 20.04 LTS as the most popular Linux distribution among Steam users, with typical hardware configurations of 16 GB RAM and 4‑core CPUs.
This article uses the 2021 Log4j vulnerability as a lens to explore the nature of open‑source software, its licensing, governance, security implications, and the benefits and responsibilities for individuals and enterprises participating in the open‑source world.
This guide walks through preparing the environment, creating necessary directories, editing Redis configuration files for both master and slave nodes, and launching a three‑node Redis cluster with appropriate authentication and replication settings.
This tutorial walks through setting up a highly available MySQL master‑master cluster using Docker containers, configuring MySQL replication, and employing Keepalived for automatic failover and virtual IP management, complete with step‑by‑step commands, configuration files, and troubleshooting tips.
This article explains several methods—ranging from insecure shortcuts to recommended practices—for hiding the MySQL password‑exposure warning that appears when invoking MySQL tools from a Linux shell, providing code examples and security considerations for each approach.
This article explains the Linux FS‑Cache subsystem, detailing how it creates local disk caches called cookies, the structures and workflows of volume, data‑file, and cache cookies, and the mechanisms for allocation, hashing, state‑machine transitions, and cleanup.
This article explores the origins and impact of four foundational Linux distributions—Slackware, Debian, Red Hat, and Arch—detailing their histories, philosophies, and lasting contributions to the open‑source ecosystem, while highlighting why they remain essential pillars of modern Linux.
The LNMP one‑click installation package V1.9 adds support for Rocky Linux, AlmaLinux, CentOS Stream 9 and several Chinese Linux distributions, introduces PHP 8.1, new PHP extensions, MySQL 5.7/8.0 binaries, IPv6 and ZeroSSL options, and provides detailed management commands for deploying and maintaining Nginx, MySQL, PHP and related services.
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 how to properly set file and process permissions for Nginx, PHP‑FPM, and MySQL on Linux servers, recommending the use of a dedicated www user group, showing configuration snippets, and illustrating how to verify running processes to enhance security and avoid permission‑related errors.
This article explains why the Linux find command is essential for backend and operations engineers, walks through a common interview question about deleting year‑old log files, and then details seven practical find usages—including searching by name, type, timestamps, size, permissions, ownership, and executing commands on matches.
This guide explains how Bash stores command history, the role of HISTSIZE and HISTFILE, and demonstrates practical uses of the ‘!’ expansion—including pattern matching, repeating specific or recent commands, combining with sudo, piping, and on‑the‑fly string substitution—to dramatically speed up command‑line workflows.
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.
