This article explains the definitions of Linux buffers and cache, how the free command reports them, and demonstrates through experiments that buffers can cache both reads and writes while cache primarily handles page caching for file reads and writes.
Linux kernel version 5.18-rc6 has been released as the weekly candidate, featuring updates to network and RDMA drivers, x86 KVM fixes, wireguard self‑tests, Btrfs patches, and various architecture and core network bug fixes, with the stable 5.18 expected in 2‑3 weeks.
This guide shows how to set up an Ubuntu 16.04 virtual machine on Windows, install QEMU, fetch a modernized Linux 0.11 source tree, and use VSCode Remote‑SSH together with GDB to debug the historic kernel without rebuilding outdated toolchains.
This article provides a comprehensive guide to Linux memory management on x86‑32 systems, covering virtual address spaces, physical address translation, memory zones, user and kernel space layouts, the buddy and slab allocators, malloc/kmalloc/vmalloc mechanisms, and useful commands for inspecting memory usage.
This article explains Linux’s storage I/O stack, defines the five core performance metrics—utilization, saturation, IOPS, throughput, and response time—and demonstrates how to monitor them using tools such as iostat, pidstat, and iotop, with practical command examples.
Learn seven practical uses of the Linux find command—from locating files by name, type, timestamps, size, permissions, and ownership to executing actions like deletion—complete with interview‑style examples and clear code snippets for mastering this essential system tool.
Learn five practical tips to prevent common Bash variable errors—such as avoiding spaces around '=', correctly defining arrays, choosing proper quoting, using $(…) instead of backticks, and steering clear of reserved environment variable names—to write reliable Linux shell scripts.
This article provides a comprehensive guide on configuring and optimizing Zabbix agent monitoring for Linux and Windows, covering agent types, passive and active modes, macro variables, LLD macros, CPU/memory/file‑system metrics, and Windows service, performance counter, and event‑log monitoring.
This article explains how to identify the root causes of Linux network latency—including transmission delays, kernel processing speed, and application handling—by using tools such as hping3, traceroute, wrk, tcpdump, and Wireshark, and offers practical steps to mitigate the delays.
This guide explains how to use the Bash built‑in test command for evaluating numeric, string, and file conditions, shows practical examples with && and || chaining, and demonstrates alternative bracket syntax for robust shell scripting.
This tutorial explains how to create a Python program that uses OpenCV to take a picture with the computer's webcam at startup, checks network connectivity, constructs an email with the photo attached, and automatically sends it, including setup for Linux auto‑start.
This guide walks through downloading, compiling, and installing Nginx from source on Linux, configuring dependencies, creating a systemd service, managing start/stop commands, understanding the directory layout, and setting up basic nginx.conf directives—including worker processes, connections, MIME types, and virtual host server_name patterns.
This guide presents a comprehensive set of Linux server optimization techniques—from kernel I/O scheduling and daemon reduction to filesystem choices, TCP tuning, and essential performance commands—helping system administrators boost efficiency, security, and reliability across diverse workloads.
This article provides a comprehensive overview of Podman, an open‑source, daemon‑less container runtime, compares it with Docker, explains key architectural differences, and offers detailed instructions on installation, configuration, common commands, rootless usage, volume handling, and migration aliases.
This article compares Podman and Docker, detailing their architectures, root privileges, security, integration with Kubernetes, image building tools, and how they can be used together, helping developers choose the appropriate container runtime for their projects.
This article explains how to use Maven profiles and the maven‑assembly‑plugin to create environment‑specific Spring Boot zip packages, configure the accompanying assembly.xml, and deploy them on Linux with a custom shenniu_publish.sh script that supports unzip, start, stop and restart operations.
This article provides an in‑depth comparison of Podman and Docker, covering their architectures, root‑less operation, security, integration with Kubernetes, support for Swarm/Compose, and practical guidance on when to choose or combine each container solution.
This article provides a step‑by‑step tutorial on setting up Prometheus and Grafana for 24/7 monitoring of Linux servers and MySQL databases, covering installation, configuration, data visualization, alerting with onealert, and common troubleshooting tips for reliable operations.
This article walks through creating a Linux packet sniffer that bypasses libpcap, explains PF_PACKET raw sockets, shows how to bind to a specific interface, enable promiscuous mode, attach a BPF filter compiled with tcpdump, and parse Ethernet and IP headers in a continuous receive loop.
The article walks through creating a lightweight, extensible Node.js command‑line utility without third‑party libraries, covering the command‑pattern design, implementation of split, upper, and word‑count commands, dynamic command loading, and best practices for modular, maintainable CLI development on Linux.
Microsoft researchers uncovered the Nimbuspwn vulnerability in systemd’s networkd-dispatcher, detailing how directory‑traversal, symlink‑race, and TOCTOU flaws let attackers replace root‑owned scripts, achieve privilege escalation, and why coordinated patching across hundreds of Linux distributions is critical.
Ubuntu 22.04 LTS, codenamed Jammy Jellyfish, introduces five distinctive capabilities—including optimized data‑driven workloads, enhanced Active Directory integration, a real‑time kernel option, updated packages and drivers, and performance boosts—that together position it as arguably the strongest long‑term support Ubuntu version to date.
This article walks through generating a heavy‑load MySQL workload, using top, iostat, and iotop to pinpoint high disk I/O, mapping OS thread IDs back to MySQL sessions, and safely killing the offending query to relieve pressure.
This guide explains how to use the Linux sleep and wait commands for pausing execution, specifying time units, handling sub‑second intervals, running periodic tasks, and synchronizing background processes, complete with practical Bash examples and detailed explanations.
Learn how to install the pinfo tool across major Linux, BSD, and macOS distributions and use it to view Texinfo documentation with syntax‑highlighted colors, including command examples, navigation shortcuts, and alias configuration for a richer command‑line experience.
This guide explains how to create and manage Bash aliases, view existing shortcuts, and replace simple aliases with parameter‑supporting Bash functions, providing practical examples and code snippets for Linux and macOS command‑line efficiency, especially in Kubernetes workflows.
This guide provides a step‑by‑step tutorial on Nginx, covering its overview, single‑instance installation, reverse proxy setup, load‑balancing configuration, static‑dynamic separation, high‑availability clustering with keepalived, detailed configuration directives, and performance considerations, complete with command‑line examples and code snippets.
This article explains how excessive Linux CPU context switches affect system performance and shows step‑by‑step how to monitor and analyze them using vmstat, pidstat, and sysbench, including interpreting voluntary versus involuntary switches and interrupt statistics.
This article explains several Linux commands—such as rm -rf, fork bombs, direct writes to block devices, and malicious script execution—that can irreversibly damage systems, detailing their effects, typical usage examples, and essential precautions to avoid catastrophic data loss.
This guide walks through downloading DTLE, generating a self‑signed SSL certificate, configuring Nomad with the certificate and key, starting the DTLE services, and verifying HTTPS access to securely protect database credentials during data transfer.
The article introduces the bat command as an enhanced, syntax‑highlighting and automatically paginated alternative to cat, explains its key features such as Git integration and non‑printable‑character display, provides installation and usage instructions on Linux, and shows how to customize its themes.
This article explains how Linux creates the illusion of multitasking by rapidly swapping CPU registers and program counters, details the three types of context switches—process, thread, and interrupt—and shows why excessive switching can significantly degrade system performance.
This guide walks through installing GitLab on a CentOS server, configuring its external URL, setting up admin credentials, performing basic GitLab operations such as disabling auto‑registration, creating projects, configuring SSH keys, testing repository cloning, and configuring webhooks and backup management.
This article explains the key Linux disk performance indicators—utilization, saturation, IOPS, throughput, and response time—and shows how to monitor them using tools such as iostat, pidstat, and iotop, including practical command examples and interpretation tips.
This guide shows how to install and run a collection of classic Linux terminal games—including Bastet (a Tetris clone), Pacman4Console, nSnake, 2048, Nudoku, Moon‑Buggy, Ninvaders, Ascii‑Patrol, Greed, and BSD Games—on Debian/Ubuntu or Fedora/RHEL/CentOS using simple package commands, providing a fun way to learn the Linux command line.
Meituan Search solves costly multi‑language maintenance by building a core C++ library, wrapping it with a C interface, and exposing the functions to Python via ctypes and to Java via JNI or JNA, enabling shared logic, easier packaging, and lower latency on Linux.
This article provides a step‑by‑step tutorial on what Anaconda and Conda are, how to install Anaconda on Linux, manage Python environments, handle packages, configure mirror sources, use Miniconda, the graphical UI, and run Jupyter Notebook, while also discussing their pros and cons.
This guide walks you through installing the open‑source NginxConfig visual tool, configuring Node.js, generating Nginx configuration files for static and dynamic proxies, and deploying them on a Linux server to simplify backend operations.
This guide explains how to install and run the beta Upgrade Tool to safely upgrade Linux Mint Debian Edition (LMDE) 4 to LMDE 5, including required package commands, graphical launch steps, post‑upgrade cleanup, and important precautions.
Discover a curated list of entertaining Linux commands—like cmatrix, xcowsay, sl, aafire, and more—complete with installation steps, usage examples, and visual demos that turn your terminal into a playful showcase.
This comprehensive guide walks you through Linux server hardening—covering account and login security, remote access safeguards, file system protection, rootkit detection tools, and step‑by‑step incident response—to help you prevent breaches and recover swiftly if an attack occurs.
This guide walks through the complete process of adding a Jenkins agent, from creating the node in the Jenkins UI and installing Java and Git on the remote machine to copying SSH keys, verifying connectivity, and testing the agent’s operation.
The article details a step‑by‑step investigation of why HTTP request latency increased after moving a Go‑based service to new hardware, focusing on DNS resolution delays, the role of DNSmasq, Go's resolver implementation, and the experiments that led to fixing the issue.
The three‑day openEuler Developer Day 2022 showcased the release of openEuler 22.03 LTS, a new ecosystem service platform, partner commercial plans, extensive SIG sessions, and a series of technical demos highlighting server, cloud, edge, and embedded scenarios across the open‑source community.
This article explains why Linux treats every thread as a process, describes the core kernel data structures task_struct, thread_info and the kernel stack, details the clone‑based creation path, and clarifies virtual address spaces, page tables, and the differences between user processes and kernel threads.
Learn how to configure and read Nginx access and error logs, including defining log formats, setting file locations, customizing log levels, parsing log fields, and using command‑line tools to monitor logs in real time, with practical examples and best‑practice recommendations.
This article explains the structure of Linux Ext2/3/4 file systems, the role of superblocks and block groups, compares hardware and software RAID, and introduces LVM for flexible storage management, highlighting both benefits and risks.
This guide explains step‑by‑step how to use built‑in command‑line tools on Windows, Linux, and macOS to list previously connected Wi‑Fi networks and reveal their stored passwords, allowing you to recover forgotten network credentials across all major operating systems.
This article compiles a comprehensive collection of practical Bash scripts—from a number‑guessing game and remote IP counting to system monitoring, user management, and one‑click LNMP deployment—providing Linux engineers with ready‑to‑use tools that boost productivity and automate routine tasks.
This article presents a systematic performance comparison of several Linux file‑transfer utilities—including scp, ftp, sftp, rsync, tftp, nc, and a Python SimpleHTTPServer—by measuring transfer times for a 50 GB single file and 51 GB spread across 51 200 one‑megabyte files, and discusses each tool’s speed, compression, encryption, and typical use cases.
This comprehensive guide walks developers through Nginx fundamentals, key features, installation on CentOS, essential commands, core configuration blocks, directive details, variable usage, upstream and proxy_pass setup, reverse proxy, load balancing strategies, caching, HTTPS, CORS, gzip compression, and the internal architecture, enabling you to confidently deploy and manage Nginx in production environments.
This tutorial walks through setting up a three‑host Linux environment, using Docker, sar, hping3, tcpdump and iptables to reproduce a SYN‑Flood DDoS attack, analyze its impact, and apply kernel and firewall tweaks to mitigate the attack.
This comprehensive guide explains Nginx's role as a high‑performance web and reverse‑proxy server, details its installation packages and step‑by‑step build process, breaks down the main nginx.conf sections, and demonstrates practical configurations for reverse proxy, load balancing, static‑dynamic separation, worker tuning, and high‑availability clustering.
This guide walks through configuring an NFS server, installing required utilities, creating a dedicated namespace, installing Helm, and deploying the nfs-client-provisioner chart to provide dynamic NFS storage for workloads in a Kubernetes cluster.
The article introduces the Python‑based tool “thefuck”, explains its purpose of automatically correcting mistyped shell commands, demonstrates common use cases, details installation steps across macOS, Ubuntu and other systems, shows how to configure it, and outlines the underlying rule‑based correction mechanisms.
This article explains Nginx's multi‑process design, detailing how the master process handles socket binding and listening while each worker creates its own epoll instance, registers events, and processes connections through a well‑structured event loop with code examples from the source tree.
This guide compiles a comprehensive set of Linux commands—using awk, grep, netstat, and other tools—to help you count unique IPs, rank page visits, filter bots, monitor connection states, calculate bandwidth, and identify high‑traffic or error‑prone resources from Apache or Nginx logs.
This article provides a detailed tutorial on installing Caddy on CentOS and Docker, configuring its powerful Caddyfile syntax, enabling HTTPS, reverse and forward proxy, gzip compression, address rewriting, and directory routing, demonstrating how Caddy can replace Nginx for modern web hosting.
This article explains how the Linux kernel’s kswapd thread is created, when it is awakened, and the detailed steps it follows—including LRU management, zone migration, balance_pgdat, and shrink functions—to reclaim memory efficiently on memory‑constrained devices.
This article introduces the ELK stack components, explains why centralized logging is essential, outlines core log‑system features, compares three ELK architectures, provides step‑by‑step installation and configuration for Filebeat, Logstash, Elasticsearch and Kibana, and demonstrates a complete pipeline using Kafka with code examples and diagrams.
This article provides a step‑by‑step guide to installing RedisInsight, configuring its environment variables, launching the service on Linux, deploying it with Kubernetes, and using its graphical interface to monitor and manage Redis clusters, keys, and memory.
Learn how to diagnose the “Address already in use” error by listing listening ports on Linux and macOS using netstat, ss, and lsof, understand port concepts, interpret command output, filter results, and find which processes occupy specific ports.
The article explains Minix’s origin as a teaching micro‑kernel OS, its evolution into MINIX 3 for higher security, its hidden role inside Intel’s Management Engine, and the resulting concerns about an invisible, privileged operating system running on most modern CPUs.
This guide explains how to locate large directories and files consuming disk space on Linux servers using commands like df, du, find, lsof, and tune2fs, and offers tips for handling hidden or deleted file usage.
This guide explains how to use tcpdump for network packet capture, covering basic usage, interface selection, host and port filtering, logical operators, saving captures to files, and real‑world troubleshooting scenarios with clear command examples.
This article outlines nine key reasons why developers favor Linux—ranging from its powerful command line and strong security to low resource usage, privacy protection, free licensing, and extensive community support—making it a reliable, developer‑friendly operating system for desktops, servers, and embedded devices.
This article explains how the Linux kernel's likely and unlikely macros, which wrap __builtin_expect, guide the compiler's branch prediction to improve cache usage and pipeline efficiency, and demonstrates the effect with sample C code and assembly output.
This article explains the structure of Linux Ext (2/3/4) file systems, the role of superblocks and block groups, compares hardware and software RAID, and introduces LVM as a flexible volume management solution, highlighting its benefits and potential risks.
This article explores memory management concepts from both operating system and MySQL perspectives, covering virtual vs physical memory, process memory usage analysis using tools like top and /proc, and experimental verification of memory allocation behaviors.
The article dissects Linux’s epoll I/O multiplexing, tracing the flow from socket creation with accept through epoll_create, epoll_ctl registration, and epoll_wait sleeping, detailing the kernel’s eventpoll object, red‑black tree, per‑socket wait‑queue callbacks that enable O(log N) registration and O(1) event delivery for tens of thousands of connections.
This guide explains how to install the lrzsz utility on a Linux server, then demonstrates uploading files via drag‑and‑drop or the rz command and downloading single or multiple files using the sz command, including pattern‑based selections.
This guide explains why Linux offers multiple shells, introduces Zsh and its powerful features, walks through installing Zsh and setting it as the default shell, and provides step‑by‑step instructions for adding Oh‑My‑Zsh, customizing themes, plugins, and managing updates or removal.
This article warns about several destructive Linux commands—such as rm ‑rf, fork bombs, overwriting block devices, and hidden shellcode—explaining their effects, providing example usages, and emphasizing the importance of understanding and testing commands in a safe environment before execution.
This article explains how Linux zero‑copy mechanisms such as DMA, sendfile, mmap and Direct I/O reduce data copies and context switches, detailing their operation, advantages, limitations, and real‑world usage in systems like Kafka and MySQL.
Learn how to install, configure, and operate RedisInsight—an intuitive Redis GUI—on Linux and Kubernetes, covering package download, environment setup, service deployment, basic usage, memory analysis, and key management, with step‑by‑step commands and visual screenshots.
This article walks through the complete process of setting up a Ceph storage cluster on the domestically‑produced Kylin v10 operating system, covering hardware preparation, host configuration, manual installation of Ceph packages, monitor, OSD, and manager deployment with all necessary command‑line examples.
This article explains the copy‑on‑write mechanism in Linux by examining page‑table structures, the fork process, and the page‑fault handling code in Linux 0.11, illustrating how the kernel uses read‑only page mappings and page‑fault interrupts to lazily duplicate memory pages.
This article explains how Linux namespaces provide resource isolation while cgroups enforce resource limits, detailing the six namespace types, relevant system calls, practical commands like unshare and cgcreate, and demonstrates CPU share control with Go code and cgroup configuration examples.
This article presents the classic "Shell Thirteen Questions" covering the definition of a shell, prompt mechanics, echo behavior, quoting rules, variable export, exec versus source, command grouping, substitution, wildcard handling, logical operators, I/O redirection, conditional statements, and loop constructs, each with clear explanations and examples.
This guide introduces Zsh, compares it with other Linux shells, explains its powerful features, and provides step‑by‑step instructions for installing Zsh, configuring it as the default shell, and enhancing it with Oh‑My‑Zsh themes and plugins.
An extensive tutorial covering Linux fundamentals, including operating system concepts, shell usage, essential commands, file management, permissions, process handling, networking, package management, compression, compilation, and advanced topics like daemon services, providing practical examples and step‑by‑step instructions for beginners and intermediate users.
This guide provides a detailed, step‑by‑step hardening strategy for Linux systems, covering distro selection, kernel choices, extensive sysctl tweaks, boot‑loader parameters, MAC policies, sandboxing, memory allocator hardening, compile‑time mitigations, root account protection, firewall rules, swap configuration, PAM policies, microcode updates, IPv6 privacy, partition mounting options, entropy sources, and physical security measures.
This article explains the Linux file I/O stack by outlining the path from user space through system calls to the kernel layers—VFS, filesystem, block layer, and SCSI—detailing each layer's role, page cache mechanisms, writeback processes, and direct I/O implementations with code examples.
This article explains how zero‑copy techniques such as DMA, sendfile, mmap and Direct I/O reduce the four data copies and context switches normally required for disk‑to‑network transfers, improving performance for systems like Kafka and MySQL while outlining their trade‑offs.
This article explains Linux memory addressing by covering logical, virtual, and physical addresses, the role of the MMU, segmentation and paging mechanisms, hardware and Linux-specific segment structures, and the 4‑level page‑table system that maps virtual memory to physical memory.
This article provides a comprehensive overview of Podman, an open‑source container runtime that runs without a daemon or root privileges, compares it with Docker, explains its architecture, and presents essential commands, deployment steps, configuration files, volume handling, and user‑namespace considerations for Linux environments.
This guide explains Linux performance optimization by defining key metrics such as throughput and latency, clarifying average load, detailing CPU context switches, describing common performance analysis tools, and providing practical methods for diagnosing and improving CPU, memory, and I/O bottlenecks in production environments.
This article explains in detail how Linux handles local network I/O for 127.0.0.1, comparing it with cross‑machine communication, describing the routing, device subsystem, driver code, and soft‑interrupt processing, and concluding with performance considerations and a discussion on eBPF acceleration.
This comprehensive guide walks you through the fundamentals of Linux, covering operating system concepts, core commands, file management, user permissions, process monitoring, networking, package management, compression, backup, and Vim editing, empowering beginners to confidently navigate and administer Linux environments.
This guide walks you through the hard‑way method for upgrading a Kubernetes cluster from version 1.22 to 1.23, covering prerequisites, master and worker node procedures, package handling, and verification steps to ensure a successful, fully controlled upgrade.
This article explains seven real‑world applications of the Linux find command, covering file name patterns, type filtering, timestamps, size, permissions, ownership, and executing actions on matched files, with clear examples for system administrators and developers.
This article analyzes why Linux reports "fork: cannot allocate memory" when the real issue is an excessive number of threads or PID allocation failures, explains the kernel's do_fork and alloc_pid implementations, and offers guidance for diagnosing and fixing such misleading ENOMEM errors.
This article provides a comprehensive guide to Nginx, covering its high‑performance architecture, reverse‑proxy concepts, load‑balancing strategies, static‑dynamic separation, installation commands, configuration file structure, practical reverse‑proxy and load‑balancing examples, and high‑availability setup with Keepalived.
This article presents a curated list of practical Linux operation tools—including Nethogs, IOzone, IOTop, IPtraf, IFTop, HTop, NMON, MultiTail, Fail2ban, Tmux, Agedu, NMap, and Httperf—detailing their purpose, download links, installation commands, and basic usage to help system administrators improve monitoring, performance testing, and security on Linux servers.
The newly disclosed Linux kernel vulnerability CVE‑2022‑0847, dubbed “Dirty Pipe,” affects kernels 5.8 and later (including many Android 12 devices), allowing unprivileged users to overwrite read‑only files and gain root privileges, with existing PoC/EXP and patches already released.
The newly disclosed CVE‑2022‑0847 “Dirty Pipe” flaw affects Linux kernels 5.8 and later—including many Android 12 devices—allowing unprivileged users to overwrite read‑only files and gain root privileges, with existing PoC/EXP, and researchers urge immediate kernel upgrades.
This guide demonstrates how to perform a full MySQL backup, create incremental backups, handle accidental database deletions, and restore the data using Percona XtraBackup on a Linux server, including detailed command-line steps and permission adjustments.
This article explains the Linux file I/O stack by outlining its clear route from user space to hardware, detailing the roles of VFS, the filesystem, the block layer, and the SCSI driver, and then dives into page cache mechanisms and code paths for both buffered and direct I/O.
The article explains why Linux’s fork() can return a misleading “fork: cannot allocate memory” error, tracing the issue to PID allocation failures in the kernel’s do_fork and alloc_pid functions, and shows how excessive threads, not actual memory shortage, trigger the problem.
This article presents nine practical Bash scripts covering DOS attack mitigation, email alerts, MySQL backups, Nginx log rotation and analysis, network traffic monitoring, server initialization, and disk usage checks across multiple hosts, each with ready-to-use code examples.
