This guide explains TCP connection states, essential Linux commands, three‑way handshake, four‑way termination, simultaneous open/close, flag meanings, common error codes, and keep‑alive techniques to help you troubleshoot and secure network services effectively.
This guide highlights ten frequent misconceptions and errors that new Linux users encounter—from avoiding the terminal and misusing root privileges to mistaking Linux for Ubuntu—and offers clear explanations on why they happen and practical advice to prevent them.
This article explains why Percona Xtrabackup backups of MySQL 5.7 can fail with "Too many open files" errors, demonstrates how to reproduce the issue under both non‑root and root users, analyzes the open‑files‑limit settings, and provides practical solutions to adjust system and user limits for successful backups.
The article explains Linus Torvalds' decision to label the next Linux kernel release as 6.0 instead of 5.20, outlines the major code additions—including support for AMD GPUs, Intel Habana Gaudi2, RISC‑V, and new power‑management features—while noting missing Rust patches and performance improvements.
The article introduces Linux cgroups as a kernel feature for limiting resources, explains their terminology and functions, and demonstrates a hands‑on experiment that creates a CPU cgroup, sets cpu.cfs_quota_us to restrict a process to roughly 25 % CPU usage, confirming effective resource control.
This guide presents a practical four‑stage Linux incident‑response workflow—identifying suspicious behavior, terminating and deleting malicious processes, sealing persistence mechanisms, and hardening the system—complete with essential shell commands and verification steps to efficiently neutralize Linux‑based malware.
This guide shows how to compile the GNU coreutils package with the advcpmv patch to enable a progress‑bar for the cp and mv commands, including downloading source, applying the patch, building, installing the patched binaries, and creating convenient aliases for everyday use.
This guide provides step‑by‑step instructions for installing Docker on CentOS and Ubuntu, configuring image accelerators for faster pulls, and using Docker commands to pull, run, list, and clean up images and containers, including tips for handling dangling and intermediate layers.
This article compiles a practical set of Linux terminal shortcuts, utilities, and techniques—including editing key bindings, sudo shortcuts, background job control, nohup, at scheduling, man page customization, htop, ranger, shutdown cancellation, process killing, REISUB, and youtube‑dl—to boost productivity for developers and system administrators.
This guide introduces the most common Linux package managers—dpkg, apt, rpm, yum, and dnf—explaining their purpose, core commands, options, and practical examples so readers can install, update, query, and remove software across Debian‑based and Red Hat‑based distributions.
This guide outlines practical steps for Linux system administrators to identify signs of compromise by examining logs, user accounts, login events, network traffic, and recovering deleted files, providing command examples for each investigative task.
GitLab’s onboarding handbook bans Windows on company devices, mandates macOS or Linux for security, outlines reasons for the restriction, and lists approved Apple and Dell hardware models along with guidelines for personal or rented equipment, emphasizing privacy, compliance, and timely delivery.
This guide shows how to create a Bash script that compresses and backs up yesterday's log files, removes the originals, and schedules the process with a daily cron job to prevent disk‑space exhaustion on Linux systems.
This article explains how Docker containers rely on Linux cgroups and namespaces for resource isolation, details CPU share and quota scheduling, and shows practical commands to inspect cgroup assignments, helping developers optimize container performance on Kubernetes.
This comprehensive guide walks you through essential Linux concepts, from understanding operating systems and distributions to mastering shell commands, file handling, user permissions, networking, process management, package installation, compression, and even Vim editor basics, empowering programmers to become proficient Linux users.
This article explains the end‑to‑end journey of a data packet in a TCP‑based chat application, identifies multiple points where packet loss can occur—from connection handshake to NIC queues—and offers practical Linux commands for diagnosing and mitigating these losses.
Learn how to protect your Linux server by disabling root SSH login, changing the default port, enforcing strong passwords, limiting login attempts, using SSH protocol 2, disabling forwarding, employing key‑based authentication, and restricting access by IP, with clear commands and configuration examples.
This comprehensive guide walks you through Linux fundamentals, covering the operating system basics, essential shell commands, file and directory manipulation, user and permission management, process monitoring, networking tools, package handling, compression, compilation, and advanced Vim editing techniques, all with clear examples and code snippets.
When a Linux server shows performance issues, the Netflix performance engineering team recommends a set of ten standard command‑line tools—uptime, dmesg, vmstat, mpstat, pidstat, iostat, free, sar (network and TCP), and top—to quickly assess system load, errors, resource saturation, and utilization within the critical first minute of investigation.
Learn three easy methods to capture screenshots on Linux—using the built‑in GNOME tool, the versatile GIMP editor, and Firefox’s native capture feature—each with step‑by‑step instructions and visual guides to help developers and writers quickly document their work.
This guide explains how to configure the SSH daemon on Fedora 33, use PuTTY on Windows to establish a secure remote console, transfer files with pscp, and create SSH tunnels for forwarding HTTP services, including detailed command examples, verification steps, and security warnings.
This article compiles a comprehensive set of Linux command‑line tricks and ready‑to‑run Bash scripts covering zombie‑process detection, email and URL extraction, web page download, HTTP header checks, POST requests, traceroute, socket communication, directory and MySQL backups, ping sweeps, disk I/O diagnostics, performance monitoring, process management, Java heap dumps, bulk tool installation, common library setup, system health checks, and advanced sed usage, providing sysadmins with practical, copy‑and‑paste solutions for everyday tasks.
The article details how Linux’s function‑graph ftrace tracer works on ARM64, explaining required kernel configs, how -pg inserts _mcount calls, the runtime patching of ftrace_graph_caller, register usage for argument passing, and return handling, and why shadow‑call‑stack must be disabled to enable precise call‑graph and timing analysis.
This article explains how TCP packets travel from user space to the destination, highlights typical points where packet loss can occur—including connection establishment, flow‑control queues, NIC buffers, and end‑to‑end network hops—and shows how to diagnose and mitigate these issues using Linux tools.
The article explains how traditional I/O incurs four data copies and context switches, and how DMA, zero‑copy techniques such as sendfile, mmap, splice, and Direct I/O reduce copying and system calls, improving performance for disk‑to‑network data transfers in Linux.
This guide explains why ordinary Linux users need sudo, how to safely edit the /etc/sudoers file with visudo, interprets each field in typical sudoers entries, and shows step‑by‑step examples for adding both password‑prompt and password‑less sudo access for a new user.
After successfully porting Linux to M1 Macs, the Asahi Linux team swiftly extended support to M2 devices, delivering a new release that enables USB, NVMe, battery management, Wi‑Fi, and basic keyboard/trackpad functionality on M2 MacBook Pro, with experimental support for M2 MacBook Air and M1 Ultra Mac Studio, while outlining current limitations and future GPU driver goals.
ByteDance engineers have contributed a series of Linux kernel patches that enable uncompressed kernels and other optimizations, reducing Kexec reboot latency from roughly 500 ms to just 15 ms, thereby minimizing server downtime for their high‑traffic services like Douyin.
This guide explains how to install, configure, and use the lightweight, Vim‑integrated terminal file manager Ranger on Linux, covering its three‑pane layout, essential commands, preview capabilities for files, images, and PDFs, as well as customization through its configuration files.
Linus Torvalds has just announced the stable release of Linux Kernel 5.19, notable for being the first kernel version released from an Apple M1‑based MacBook, and it brings extensive low‑level optimizations, new CPU and GPU support, Zstd compression, and critical security fixes.
This comprehensive guide walks you through installing Docker on various operating systems, configuring image accelerators for faster pulls, and mastering Docker image management—including pulling, running, listing, filtering, and cleaning up images and containers—while addressing platform‑specific considerations.
This article traces the 20‑year evolution of container technology—from early Unix chroot and FreeBSD jail, through Linux namespaces, cgroups and Docker’s image system, to modern orchestration with Kubernetes and cloud‑native runtimes—explaining core concepts, architectures, and best‑practice guidelines for building and managing containers.
This guide presents four practical Linux techniques—including fast directory navigation with the bd command, advanced cd shortcuts, multi‑terminal management with Terminator, and custom shell scripts—to streamline development workflows and enhance overall efficiency.
When a Linux server suddenly spikes in load, this guide shows how to pinpoint the root cause within a minute by running ten key commands that reveal CPU, memory, disk I/O, and network metrics, enabling rapid performance troubleshooting.
This article explains common concurrency models, thread‑pool and coroutine techniques, and various Linux I/O models—including blocking, non‑blocking, multiplexing, and asynchronous I/O—highlighting their trade‑offs and practical usage in high‑performance backend systems.
A comprehensive collection of essential Linux commands covering system shutdown, CPU and kernel inspection, file and directory management, networking tools, performance monitoring, user administration, and common shell utilities, all organized for quick reference by developers and sysadmins.
This guide explains how to automate common Linux tasks such as configuring startup services with chkconfig and rc.local, scheduling one‑off jobs using at, and setting recurring jobs with crontab, including command syntax, examples, and best‑practice tips for reliable system maintenance.
This tutorial walks you through checking system requirements, using one‑click scripts or manual steps to install Docker CE on CentOS 7, starting the service, verifying with a hello‑world container, and provides common Docker commands for ongoing use.
This guide walks through eight essential steps to harden SSH on Linux servers, including disabling root login, changing the default port, restricting password usage, limiting authentication attempts, enforcing protocol 2, disabling forwarding, using key-based authentication, and applying IP-based access controls.
This article explores fun terminal tools such as Cool Retro Term, Genact, Hollywood, and Blessed‑contrib that let you fill your screen with fake code, progress bars, and system monitors to mimic the dramatic hacker displays seen in movies.
This article explains the Von Neumann computer architecture, the role of the operating system, process creation and control blocks, various process states, priority and nice values, as well as virtual address spaces and their relationship to physical memory, using Linux examples and diagrams.
This guide provides step‑by‑step instructions for installing Docker on CentOS and Ubuntu, configuring accelerated image mirrors, managing Docker images—including listing, tagging, and removing—while covering essential commands, storage considerations, and best practices for both systemd and upstart environments.
This guide explains how to monitor Linux CPU usage, scheduler queues, lock contention, network I/O, and disk I/O using graphical tools and command‑line utilities such as gnome‑system‑monitor, vmstat, pidstat, nicstat, and iostat, with syntax, parameters, example outputs, and installation steps.
This guide explains the differences between the Linux commands su and sudo, shows how to create test users, switch between login and non‑login shells, use the -c option, configure sudo privileges with visudo, and compare security implications of each method.
This guide explains how to view IP addresses on Windows and Linux, compares commands like ipconfig, ifconfig, and ip addr, and delves into networking fundamentals such as CIDR, public vs private IP ranges, MAC addresses, and interface flags.
This article provides a comprehensive tutorial on preparing the environment, installing DataX and DataX‑web, configuring MySQL, JDK, Maven, and Python, deploying the services on Linux, and using the web UI to create data sources, build JSON jobs, monitor execution, and manage users.
This guide presents four practical Linux techniques—including the bd shortcut for fast directory jumps, Terminator for multi‑pane terminals, Typora for seamless Markdown editing, and a compact Vim configuration—plus custom shell commands, providing clear commands, scripts, and shortcuts to streamline everyday development workflows.
This guide explains how to use tmux on Linux—including creating, detaching, attaching, renaming, and killing sessions, managing windows and panes with handy keyboard shortcuts—plus a quick tip for identifying physical network interfaces using ethtool.
This tutorial shows how to patch GNU coreutils using the open‑source advcpmv project so that the cp and mv commands display a progress bar, including step‑by‑step compilation, alias configuration, and sample output demonstrating total and per‑file progress.
This guide explains what a Linux driver is, classifies character, block and network devices, walks through the open() system call flow from user space to the kernel’s VFS and driver list, and shows how to write, compile, and load a simple character device driver module.
This article surveys the major Chinese open‑source Linux distributions that serve as CentOS replacements—including OpenEuler, Anolis OS, UnionTech UOS, Alibaba Cloud Linux, TencentOS, KylinOS, Deepin, Red Flag and Ubuntu‑Kylin—detailing their origins, compatibility, key features, and typical cloud or enterprise use cases.
This article walks you through preparing hardware, partitioning the disk, downloading an Ubuntu ISO, creating a bootable USB with UltraISO or Rufus, configuring BIOS/UEFI settings, and completing the Ubuntu installation alongside an existing Windows 7/10 system.
This guide lists ten indispensable Ubuntu desktop applications—from GNOME Tweaks and Steam to VLC and Kdenlive—explaining their key features, typical use cases, and providing exact terminal commands for quick installation via apt, Flatpak or Snap.
This guide explains why the default SSH configuration is risky and provides eight concrete actions—including disabling root login, changing the default port, limiting authentication attempts, and using key‑based authentication—to secure Linux servers against common attacks.
The article explains how Vivo’s data centers use the Linux EDAC framework—combined with sysfs mapping, driver selection, and APEI error‑injection testing—to monitor per‑DIMM correctable and uncorrectable errors, enabling early fault prediction, reducing server crashes, and supporting broader RAS strategies.
This talk walks through Docker’s appeal, its rise to popularity, the underlying container technology history, core architecture, networking, namespaces, cgroups, and common commands, illustrating how containers streamline deployment compared to traditional VMs and why Docker remains pivotal in cloud-native environments.
Linux is generally more secure than other desktop operating systems, so many users wonder whether antivirus software or a firewall is necessary; this article explains the technical reasons why Linux typically does not need them, outlines the limits of protection, and offers practical security tips.
This guide explains why the “Address already in use” message appears, defines listening ports, and shows step‑by‑step how to use netstat, ss, and lsof commands to list, filter, and pinpoint the processes occupying specific ports on Linux and macOS systems.
This guide explains how to prepare the environment, install required dependencies and a newer GCC toolset, and then compile, build, and install Percona XtraBackup 8.0 from source on an Aarch64 Kylin v10 system, including troubleshooting tips for common issues.
This article explains the Linux boot sequence on x86 hardware, covering BIOS ROM loading, real‑mode memory layout, the MBR, the setup() assembly routine, transition to protected mode, and the startup_32() function that prepares paging before the kernel begins execution.
This article introduces twelve practical Linux operation tools—including Nethogs, IOZone, IOTop, IPtraf, IFTop, HTop, NMON, MultiTail, Fail2ban, Tmux, Agedu, and NMap—detailing their purpose, installation steps, and usage commands to help system administrators efficiently monitor and secure their servers.
While Linux is generally more secure than other operating systems, many users wonder whether antivirus software or a firewall is necessary; this article explains why Linux desktop malware is rare, how package managers improve safety, the limited effectiveness of antivirus tools, and when a firewall truly matters.
This guide explains the purpose of the ls -lrt command, breaks down its -l, -r, and -t options, shows how they combine to list directory contents sorted by time with the newest files at the bottom, and provides concrete command‑line examples for practical use.
This guide introduces the Linux ‘cheat’ command—a concise cheat‑sheet tool that replaces lengthy man pages, shows how to install it via snap, demonstrates usage with examples like netstat, and explains how to edit, remove, or search cheat‑sheets for any command.
The article explains how requesting memory larger than physical RAM interacts with virtual memory, page faults, swap mechanisms, and OOM handling on 32‑bit and 64‑bit operating systems, illustrated with C code experiments and Linux/macOS observations.
This guide explains what WSL 2 is, its advantages over virtual machines, and provides step‑by‑step instructions for installing WSL, selecting a Linux distribution, and integrating it with VS Code and Docker to create a seamless development environment on Windows.
This article explains the concepts of synchronous and asynchronous execution, blocking and non‑blocking operations, user and kernel space, process switching, file descriptors, cache I/O, and compares various Linux I/O models such as blocking, non‑blocking, multiplexing, signal‑driven and asynchronous I/O, including the differences among select, poll and epoll.
This guide walks you through the most common Linux system‑monitoring utilities—top, htop, vmstat, dstat, glances and sar—detailing their purpose, syntax, frequently used options, and practical command‑line examples so you can quickly assess CPU, memory, I/O, and overall system health.
The article traces Microsoft’s dramatic shift from denouncing Linux as a cancer in the early 2000s to embracing open‑source technologies and making Linux a cornerstone of Azure, highlighting strategic changes under Satya Nadella and the broader impact on the company’s value and culture.
This guide explains how the ls -lrt command works, breaks down its -l, -r, and -t options, shows example outputs, and demonstrates how to sort directory listings by time, making file management in Linux faster and more efficient.
This article walks through the complete GCC toolchain workflow—preprocessing, compilation, assembly, and linking—using a simple C "Hello World" program, explains the roles of GCC, Binutils and the C runtime, and shows how to inspect the resulting ELF binary with common Linux utilities.
This guide introduces Bpytop, the Python‑based, visually appealing terminal resource monitor, outlines its key features, explains the required prerequisites, and provides step‑by‑step instructions—including code snippets—for installing and operating the tool on Linux systems.
Researchers from Intezer and BlackBerry uncovered Symbiote, a novel Linux rootkit that loads as a shared library via LD_PRELOAD, hijacks libc and libpcap, uses BPF hooking to hide malicious traffic, and targets credential theft and remote access, especially in Latin American financial sectors.
The article uses a cultural analogy about Emperor Yongzheng to introduce the concept of mapping, then explains how Linux's mmap can map a physical GPIO register into user space, provides a complete code example for toggling an LED, and discusses mmap's broader uses and performance trade‑offs.
This article explains Linux storage hierarchy, the roles of user‑space and kernel caches, the three‑layer I/O stack, page‑cache synchronization policies, file‑operation atomicity, locking mechanisms, and performance testing techniques for HDD and SSD devices.
This guide walks you through checking the current XFS root size, enlarging the virtual disk in VMware, installing the growpart utility, extending the root partition, resizing the XFS filesystem with xfs_growfs, and verifying the new 40 GB capacity, while noting important constraints such as the need for no following partitions.
The article explains how Linux’s cpuidle framework manages idle CPUs by selecting multi‑level C‑states through core, driver, and governor modules—detailing ladder and menu governor algorithms, latency‑based state selection, and a real‑world case where mis‑configured latency requests prevent deepest idle entry.
This guide introduces the MTR network diagnostic tool, explains how to install it on Windows, Linux, macOS and Android, demonstrates basic commands and key parameters, and shows how to interpret loss, latency and stability metrics to troubleshoot routing problems effectively.
After Microsoft halted sales and blocked Windows downloads in Russia, piracy surged and Russian government bodies began rapidly shifting to Linux, especially Astra Linux, signing billion‑ruble contracts while facing the complex challenges of migrating embedded, software‑controlled systems.
This article introduces systemd, explains its advantages over init, details unit concepts and key commands, outlines configuration file structures, and provides three hands‑on examples—managing Nginx, Tomcat, and a custom Java JAR service—demonstrating practical systemd usage on CentOS 7.
This step‑by‑step guide explains how to verify your CentOS 8 environment, download and prepare Oracle's centos2ol.sh migration script, run it to replace packages and switch to the Oracle Linux kernel, reboot, and confirm the successful migration to Oracle Linux Server with UEK.
This article explains the epoll interface, its underlying data structures, the three-step usage pattern, the differences between level‑triggered and edge‑triggered modes, the reactor model, and provides a complete C demo, helping developers efficiently handle millions of concurrent TCP connections on Linux.
By configuring Linux Transparent Huge Pages and tuning kernel parameters, large‑scale cloud services can cut TLB misses and page‑table overhead, achieving over ten percent CPU and latency reductions while limiting memory growth to about ten percent, as demonstrated in Baidu’s production recommendation system.
This article describes a complete solution for per‑process monitoring of CPU, memory, disk I/O and network usage on Linux servers, covering the shortcomings of existing tools, data collection methods, aggregation logic, storage in MySQL, visualization with Grafana, deployment steps, and operational best practices.
This article provides a detailed, English-language tutorial on preparing the network environment, creating necessary directories, configuring Redis instance files, launching six Redis nodes, and initializing a clustered Redis deployment across three servers using Linux command‑line tools.
Linux kernel version 5.19 has entered its fifth release candidate (RC5), with Linus Torvalds noting a low patch count focused on driver fixes, architecture updates, and filesystem and networking improvements, and introducing support for LoongArch CPUs, Apple NVMe, Zstd-compressed firmware, and FAT32 creation timestamps, with the stable release slated for late July.
This article explains what eBPF is, why it was created, its core characteristics, common use cases such as network optimization, fault diagnosis, security control and performance monitoring, and provides practical step‑by‑step guidance, tooling commands, program types, and ecosystem resources for leveraging eBPF in cloud‑native environments.
This guide explains how to replace the default PHP 5.6 with PHP 7.3 on a Linux server by editing the system profile, updating the PATH variable, and reloading the profile, including the necessary command-line steps and code snippets.
This article explains how TCP connections are identified by a four‑tuple, why the 65535 port limit only applies to client‑side connections, the theoretical 2⁴⁸ limit for servers, and how actual concurrency is constrained by memory, file descriptors and port reuse.
This guide provides concise English explanations of dozens of essential Linux commands—including compression tools, process utilities, and network utilities—covering their purpose, syntax, key options, and practical usage examples for system administrators and developers.
This tutorial explains how to set up software load balancing using HAProxy and achieve high availability with Keepalived, covering architecture, installation, configuration files, VRRP failover, load‑balancing algorithms, session persistence, SSL offloading, and traffic routing.
This guide compiles a comprehensive set of Linux shell commands for analyzing Apache access logs, helping you count unique IPs, identify popular pages, detect suspicious traffic, monitor connection states, measure bandwidth, and extract detailed usage statistics for effective server operations.
This article explains that the 65535 TCP port limit does not directly cap concurrent connections, detailing how TCP connections are identified by a four‑tuple, the theoretical maximums for client and server sides, and why actual limits depend on memory, file descriptors, and port reuse.
Learn practical methods to boost server performance by selecting appropriate hardware configurations, analyzing CPU, memory, disk I/O and network loads, and fine‑tuning kernel parameters such as file limits and TCP settings, with step‑by‑step commands and monitoring tools like htop, iostat, and nload.
The article lists several destructive Linux commands—such as rm -rf, fork bomb, direct writes to block devices, and hidden shellcode—explains their catastrophic effects, provides exact syntax examples, and warns readers to understand and test them carefully before execution.
This article provides a comprehensive guide to fundamental Linux command‑line tools—including ls, pwd, cd, grep, cat, more, echo, hostname, touch, df, and vim—explaining their purpose, common options, and practical usage examples with sample outputs for system administrators and developers.
This guide explains why you should avoid compiling GCC yourself and shows step‑by‑step how to use Red Hat's Developer Toolset or gcc‑toolset to install, switch, and activate newer GCC versions on both CentOS 7 and CentOS 8, including temporary and permanent activation methods.
An exposed Docker security flaw allows services bound to 127.0.0.1 via the -p flag to be accessed externally through iptables rules, as demonstrated by a PostgreSQL container proof‑of‑concept, and the article proposes stricter iptables configurations and default localhost binding to mitigate the risk.
Learn how to download XShell, install it on Windows, configure a session, and connect to a Linux server, with step‑by‑step instructions, screenshots, and tips for handling common issues such as SSH X11 forwarding errors.
Linus Torvalds hints at integrating Rust into the upcoming Linux 5.20 kernel, outlining the language's safety benefits, development timeline, and the broader impact on kernel architecture while emphasizing that a full rewrite is not planned.
