This guide explains how to use Logrotate on Linux for automatic log file rotation, covering default configuration files, key options, example setups for Nginx, PHP, Tomcat, system logs, custom shell and Python scripts, cron scheduling, and troubleshooting techniques to ensure logs are rotated reliably.
This comprehensive guide breaks down the four main parts of a Linux system—kernel, shell, filesystem and applications—detailing kernel subsystems such as memory and process management, shell variants, file types, directory hierarchy, partition handling, VFS, mounting procedures, link types and essential command‑line tools, while also touching on application bundles and kernel parameter tuning.
This article provides a comprehensive overview of Linux system architecture, covering the kernel, memory and process management, virtual file system, device drivers, networking, shell types, filesystem hierarchy, partitioning, mounting, and common commands, offering a solid foundation for understanding Linux fundamentals.
This article explains how a user‑level program becomes a Linux process, how the kernel views it through ELF loading, the role of the task_struct data structure, its key fields, task state transitions, and how the kernel stores the descriptor in memory.
This guide explains how regular expressions can be used on a CentOS 8 system to quickly retrieve network details, disk usage, user information, file permissions, and other key data through concise shell commands and pattern matching techniques.
This guide explains how to configure Linux system limits, kernel TCP parameters, and I/O event mechanisms to enable a single process to handle a large number of simultaneous connections, improving server throughput and stability under high‑concurrency workloads.
This article enumerates the core Linux system metrics collected by the Open‑Falcon agent—including CPU, disk, memory, network, kernel, and process statistics—explaining how each metric is derived from /proc or other system tools and why it matters for reliable operations monitoring.
Understanding Linux load average and CPU utilization, this guide explains process states, how load is calculated, the difference between load and CPU usage, common bottlenecks, and practical troubleshooting steps using tools like top, vmstat, pidstat, iostat, and perf to pinpoint performance issues.
A concise collection of Linux command-line one‑liners demonstrates how to extract IPv4 addresses, disk usage, user information, permissions, and pattern matches using regular expressions and tools like ifconfig, df, cat, cut, sort, and egrep.
The article explains that kernel code must copy user‑space buffers with copy_from_user rather than using memcpy, covering the necessity of copying, the built‑in access checks, page‑fault handling, security implications, and modern hardware safeguards like PAN.
This article explains why learning Linux commands can be overwhelming for beginners, introduces the open‑source Kmdr CLI tool that explains commands and their options directly in the terminal, and provides step‑by‑step installation and usage examples—including npm, Homebrew, and Docker approaches.
This article provides a comprehensive overview of Linux file system architecture, covering basic concepts, directory structures, absolute and relative paths, linking, VFS abstraction, ext2/ext4 implementations, locking mechanisms, key system calls, and network file systems like NFS, illustrating how they interact within the kernel.
The article explains how a MySQL instance on a CentOS 7.1 VM repeatedly suffered connection failures due to out‑of‑memory (OOM) events triggered by a mis‑configured 40 GB hugepage allocation that remained reserved for MySQL even after the large‑page setting was disabled.
The Android kernel suspend process begins when user‑space writes “mem” to /sys/power/state, triggering an autosuspend loop that validates wakeup_count, logs pending wakeups, freezes filesystems and threads, sequentially calls device suspend callbacks, prepares platform‑specific operations, disables CPUs and interrupts, saves core state, and finally enters the low‑power s2ram state.
This tutorial presents a collection of eleven practical Linux commands and regular‑expression patterns that retrieve network details, disk usage, user information, file permissions, and IP address matching, each illustrated with clear examples and output screenshots.
NVFS is a Red Hat‑led Linux file system designed for DAX‑based persistent‑memory devices, mapping the whole device into a linear address space to bypass the kernel block layer, and delivering performance far superior to EXT2/EXT4/XFS and the earlier NOVA file system.
This guide explains sandbox fundamentals, compares Windows and Adobe Reader sandboxes, and provides step‑by‑step instructions for installing and configuring a Cuckoo Linux sandbox on Ubuntu, including SystemTap syscall monitoring and signature creation illustrated with a Gonnacry ransomware case study.
This tutorial walks through the fundamentals of Nginx, explains its main features, details version choices, outlines the directory layout, and provides complete step‑by‑step commands for installing and configuring Nginx on both Windows and CentOS Linux environments.
The article lists essential tools for Java developers in 2020, covering IDEs, version control, CI, testing, build automation, containerization, and operating system basics, and explains why each tool is valuable for both core and web Java programmers.
This article provides a comprehensive, illustrated explanation of how Linux receives network packets—from hardware DMA and interrupt handling through soft‑interrupt processing, NAPI polling, protocol stack registration, and finally delivery to user‑space via recvfrom—detailing each kernel component and relevant source code.
This article explains the core components of Linux file systems—including inodes, directory entries, virtual file system layers, storage allocation methods, free‑space management, block‑group layout, directory handling, hard and symbolic links, and various I/O models—providing a comprehensive guide for developers and system engineers.
The article explains why a Linux system may report a full disk even after deleting files, detailing how open file handles keep space occupied, and walks through the virtual file system architecture—including superblocks, inodes, file and dentry objects—while demonstrating diagnostic commands like df, du, lsof, and illustrating link types and file‑process interactions.
This tutorial walks you through checking the pre‑installed Python version, locating its binaries, downloading Python 3.6.5 source, installing required dependencies, compiling and installing the interpreter, creating symlinks, and configuring environment variables on a Linux system.
This guide provides Java backend developers with a comprehensive collection of practical Linux commands for CentOS 7.6, covering system service management, file operations, compression, disk and network monitoring, as well as software installation and package management, all illustrated with clear examples and screenshots.
This article explores the original 1,000‑line Git source from its first commit, showing how to obtain, compile, and analyze the core commands and objects—init‑db, update‑cache, cat‑file, show‑diff, write‑tree, read‑tree, commit‑tree—while explaining Git’s design principles, storage layout, SHA‑1 naming, and the limitations of the initial implementation.
This guide walks through installing msmtp, configuring mutt to send emails, using the free command to monitor memory and swap, creating Bash scripts for logging and alerting, and scheduling the tasks with cron for continuous system health reporting.
This guide walks you through installing the msmtp email client, configuring mutt to send mail, using the free command to monitor system memory, creating Bash scripts for memory and swap alerts, and scheduling these checks with cron on a Linux server.
This guide introduces thirteen practical Linux operation tools—including Nethogs, IOZone, IOTop, IPtraf, IFTop, HTop, NMON, MultiTail, Fail2ban, Tmux, Agedu, NMap, and Httperf—detailing their purpose, installation commands, usage examples, and download sources to help administrators efficiently monitor and manage system resources.
This guide explains how to tune Linux for high‑concurrency workloads by disabling unnecessary iptables, raising the per‑process file descriptor limit, modifying kernel TCP parameters via sysctl, and choosing appropriate I/O event mechanisms such as epoll or AIO.
This guide walks through the most common Linux shell tools for text processing—including find, grep, xargs, sort, uniq, tr, cut, paste, wc, sed, and awk—explaining their core options, practical examples, and how to combine them for powerful command‑line workflows.
This guide presents a concise collection of practical CentOS 8 Linux commands and regular‑expression patterns, showing how to retrieve IP addresses, disk usage, user information, file permissions, and more, complete with command examples and visual output screenshots.
This guide walks you through Linux process fundamentals and equips you with practical commands—ps, strace, pstack, pstree, gdb, and /proc file inspection—to diagnose, trace, and debug running programs step by step.
This guide explains what SSH is, its login mechanism, basic command syntax, and demonstrates remote login, local and remote port forwarding, dynamic forwarding, and common SSH operations with practical examples and troubleshooting tips for Linux environments.
Learn step‑by‑step how to activate the root user on Ubuntu, assign a password, configure sudo for password‑less access, and later lock or disable the root account by expiring its password, with clear command examples and safety tips.
This article explains how sudo and su differ in password requirements, default behavior, scope of privilege elevation, environment handling, and usage syntax, providing clear examples and guidance for choosing the appropriate command in Linux system administration.
This guide walks you through creating and using a one‑click installation package that sets up essential development services—MySQL, Nginx, JDK, Redis, RabbitMQ, and a SpringBoot jar—on Ubuntu 16.x, detailing directory structure, required prerequisites, individual start/stop scripts, and customization options for small‑scale deployments.
This guide explains the key differences between sudo and su on Linux, covering password requirements, default behaviors, environment handling, command syntax variations, and practical usage tips for switching users or executing privileged commands safely.
This guide explains how to configure Linux for high‑concurrency workloads by increasing the maximum open files limit, adjusting kernel TCP parameters, and selecting appropriate I/O event mechanisms such as epoll or AIO.
Depending on network constraints like corporate NAT, Docker may require proxy settings; this guide explains three proxy scenarios—daemon (dockerd) via systemd, container-level via config.json, and build-time via build arguments—detailing the necessary environment variables, configuration files, and command-line options for Linux environments.
Learn a quick, unconventional method to conceal a Linux process from userspace by simply altering its PID with a one‑line SystemTap script, demonstrating how modifying kernel task structures can make the process invisible in procfs and evade standard detection tools.
This tutorial walks through setting up a four‑node Kafka cluster—including Zookeeper installation, broker configuration, service startup, replication settings, fault handling, and leader election—using Linux commands and detailed code snippets to help readers build a production‑ready streaming platform.
This comprehensive guide explores Linux’s four core components—kernel, shell, filesystem, and applications—detailing kernel architecture, memory and process management, VFS, device drivers, network interfaces, shell types, file types, directory structures, mounting, and essential command-line tools for system administration.
This article explains how Linux command‑line pipelines work, highlights the limitations of traditional shell scripts, and demonstrates how a concise Python script can replace them for counting unique users in log files while remaining easy to read, reusable, and powerful.
Learn how to speed up navigation with the "z" command, enhance Vim with a ready-made config, add a clear MySQL prompt, accurately check OS version, and visualize disk usage using concise terminal commands and scripts.
This article provides a comprehensive overview of Linux file systems, covering VFS, directory hierarchy, absolute and relative paths, symbolic links, mounting, file locking, and the essential system calls such as creat, open, read, write, lseek, stat, pipe, and fcntl.
This guide shows how to speed up Linux command‑line work by installing the z directory‑jump script, applying a feature‑rich Vim configuration, customizing MySQL prompts, accurately checking OS version, and using a more visual disk‑usage tool.
This guide compiles the most frequently used Linux commands for file navigation, content viewing, searching, permission handling, text processing, archiving, system control, and process management, providing clear examples that help operations staff work more efficiently and confidently.
This article demonstrates how to recover mistakenly deleted InnoDB .ibd files by locating the open file handle through Linux procfs, locking database traffic, copying the hidden file, and restoring it to a running MySQL instance.
This guide explains multiple ways to copy and paste text and commands in Linux terminals, covering keyboard shortcuts like Ctrl+Shift+C/V, right‑click context menus, mouse middle‑click pasting, terminal‑specific key bindings, and special cases such as Putty and flow‑control keys.
The article explains why Linux’s free command reports far higher used memory than the RSS values shown by ps aux, by breaking down buffers, cache, slab allocations, page tables and shared libraries, and provides shell scripts to calculate each component.
Linus Torvalds highlighted the generational challenge of Linux kernel maintenance, the difficulty of finding new maintainers, the importance of trust, the continued dominance of C with emerging Rust support, and previewed the massive upcoming 5.8 release with its new hardware and feature updates.
This article introduces SSH as an encrypted network protocol, explains its login principles, demonstrates basic command usage, and provides detailed examples of remote login, local and remote port forwarding, dynamic forwarding, remote operations, and security considerations for Linux systems.
This guide walks you through four essential Linux commands—wall, mesg, write, and talk/ytalk—detailing how to broadcast messages, control incoming chats, send direct text, and start interactive sessions, complete with syntax examples and usage tips.
This guide walks you through ten essential Linux command‑line tools—such as uptime, vmstat, iostat, and top—showing how Netflix’s performance engineers use them to quickly assess system load, resource saturation, and errors within the first minute of investigation.
This guide explains how to identify Nginx bottlenecks, apply a series of configuration and kernel tweaks—including worker processes, event model, connection limits, gzip, proxy timeouts, and sysctl settings—and then validate the improvements with Apache ab load testing to achieve up to 100 000 concurrent requests.
This comprehensive guide explains how to start, stop, and configure Apache HTTP on Windows and UNIX, covering default ports, key configuration files, version checking, security hardening, logging, virtual hosts, proxy setup, performance tuning, and common troubleshooting techniques.
This article walks through ten common Linux shell interview questions, covering script interruption, file header removal, line length checking, viewing non‑printing characters, directory permissions, process states, cut usage, cmp vs diff, echo vs ls, and a brief explanation of inodes.
This article traces the early emergence of domestic Linux‑based operating systems in China, examines why most early distributions faded, analyzes the ecosystem and policy shifts since 2015, and reviews the latest domestic CPUs and the unified UOS platform that aim to reshape the market.
The weekly roundup covers China's first financial blockchain standard, Intel's 11th‑gen Tiger Lake CPUs, Linux From Scratch v10, Microsoft's deep‑fake detection tool, a record‑scale brain‑inspired computer, a global traffic dip caused by a Level 3 BGP outage, TSMC's AI‑powered chip‑data processing, advances in Bayesian neural networks, and a SIGIR paper on two‑stage question matching.
This guide explains how to install, start, name, detach, reattach, nest, and close GNU Screen sessions on Linux, enabling you to keep long‑running processes alive across network interruptions and efficiently manage multiple terminal tasks in a single window.
This guide walks you through installing Hugo, creating a static blog, configuring Nginx as a reverse proxy, setting up Gitbook for documentation, and integrating Qiniu cloud storage for image handling, all on a Linux server using personal domain access.
This guide introduces four powerful open‑source terminal file managers for Linux—nnn, ranger, cfiles, and dfshow—detailing their key features, platform support, command‑line usage, and where to find their source repositories.
bashtop is a Bash‑written Linux resource monitor that visualizes CPU, memory, disk, network and process usage, offers a game‑inspired UI with fast navigation, configurable settings, and real‑time graphs, and is available on GitHub with detailed configuration examples and usage instructions.
When a large file is deleted on a Linux server but the '/' partition still reports 100% usage, a running process likely still holds the file open, preventing space reclamation; this article explains the cause, shows how to find deleted‑but‑in‑use files with lsof, and offers recovery steps such as killing processes, restarting services, truncating logs, and adjusting reserved block percentages.
The article shares a personal journey of using the Deepin Linux distribution for everyday development, communication, and entertainment, demonstrating its graphical interface, extensive software support, Android app compatibility, and various efficiency and freedom advantages that make it a viable Windows alternative.
PELT (Per‑Entity Load Tracking) replaces the coarse per‑run‑queue load model in Linux’s CFS scheduler with fine‑grained, decay‑based load and utility measurements for each scheduling entity, enabling more accurate load‑balancing, CPU‑frequency decisions, and hierarchical group scheduling across heterogeneous cores.
This article introduces seven visually impressive Linux distributions—elementary OS, Deepin, Pop!_OS, Manjaro, KDE Neon, Zorin OS, and Nitrux—highlighting their unique designs, underlying bases, key features, and where to download them, helping developers choose a beautiful desktop environment.
A roundup of recent tech news covering a Cisco sabotage case, a London data‑center fire, Linux's 29th anniversary, Gartner's China ICT trends, major cloud investments, Windows 95 milestones, Didi's GPU server launch, Hainan's DNS project, Dell’Oro's market report, executive share reductions, and an upcoming global operations conference.
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.
