This article provides an overview of InfiniBand and Remote Direct Memory Access (RDMA), explains their underlying protocols and hardware, and offers detailed step‑by‑step guidance for configuring InfiniBand, RDMA, RoCE, and related services on Red Hat Enterprise Linux systems.
This article explains the fundamentals of Linux interrupt handling, covering the distinction between hardware and software interrupts, the processing flow of hard IRQs, maskable versus non‑maskable interrupts, the need for deferred execution, and a deep dive into softirqs, tasklets, and workqueues with code examples and performance considerations.
This article documents a real‑world Linux server compromise, detailing the observed symptoms, forensic commands, malicious scripts, file‑locking tricks, and a step‑by‑step remediation process including SSH hardening, cron cleanup, chattr usage, and preventive security recommendations.
This guide shows how to identify a Linux process’s PID and safely terminate it using kill, killall, or pkill, covering signal options, common signals like SIGTERM and SIGKILL, and practical command examples for both foreground and background processes.
This guide walks beginners through the complete process of publishing a website online, covering domain registration and ICP filing, DNS configuration, selecting and configuring a cloud server, installing Java and Tomcat, and finally uploading the site source files via FTP.
A whimsical tale explains how Docker solves application deployment pain by using chroot/pivot_root for filesystem isolation, Linux namespaces to hide host resources, and cgroups to limit CPU, memory, and I/O, illustrating core container technologies with practical code snippets.
This article chronicles the development of operating systems from the early Z1 computer without an OS to modern platforms like Linux, Android, iOS, and Chrome OS, highlighting key milestones, innovations, and the impact on computing over the past decades.
Mist is a command‑line helper for Debian‑based systems that brings AUR‑style package discovery and management to Ubuntu and Debian, allowing users to search, install, update, and remove packages from the makedeb Package Repository with simple commands.
Linux kernel 6.0, released on October 2 by Linus Torvalds, brings major enhancements such as Rust support, ARM and RISC‑V improvements, CPU fault detection, better ACPI power management, SMB3 performance, Intel Arc GPU certification, and even Atari PC optimizations, marking it as one of the most commit‑heavy releases in recent history.
This article explains the fundamentals of Linux interrupt handling, covering hardware and software interrupt types, the IRQ processing flow, maskable versus non‑maskable interrupts, the need for deferred execution, and detailed mechanisms of softirqs, tasklets, and workqueues with practical code examples.
Drawing from three and a half years of Linux operations, this guide outlines practical standards for testing, confirming commands, avoiding concurrent edits, mandatory backups, data safety, security hardening, continuous monitoring, performance tuning, and the right mindset to keep production environments stable and secure.
This article compares macOS and Linux by exploring their histories, kernel architectures, openness, hardware requirements, software ecosystems, user experience, customizability, gaming support, package management, and update policies, helping readers decide which operating system best fits their needs.
This guide explains how to terminate Linux processes using the kill, killall, and pkill commands, covering signal types, how to find process IDs, command syntax, and practical examples for both foreground and background tasks.
This article walks through installing BIND, configuring the named.conf file, creating forward and reverse zone files, setting up a master DNS server and a slave server, starting the services, and verifying the setup with nslookup, including a fail‑over test.
The article demonstrates how to examine a running Go program’s memory layout by defining example structs, using unsafe.Sizeof/Alignof, dumping writable regions via a Bash script and GDB, and locating fields and string constants in the resulting memory dumps to verify object representation.
This article explores how Kubernetes Pods differ from simple containers by examining their underlying implementation, shared network and IPC namespaces, cgroup hierarchies, and the role of the pause sandbox, while also demonstrating how similar pod-like behavior can be achieved using Docker and cgroup tools.
This article outlines the fundamental differences between Linux and Unix, covering topics such as the non‑standard Bash shell, the absence of long‑option support in Unix, variations in Make and C compilers, the distinction between GNU and Linux, and the trademarked UNIX name, providing a concise guide for developers navigating these operating systems.
This article explains how Kubernetes forwards packets from the initial web request through pod network namespaces, the role of the pause container, veth pairs, bridges, CNI plugins, and iptables‑based service NAT, providing a step‑by‑step view of intra‑cluster and external traffic handling.
This guide explains the ping utility’s core functions, interprets its output fields such as bytes, time, and TTL, and demonstrates advanced options like -t, -a, -n, -l, -r, as well as batch pinging of IP ranges for network troubleshooting.
This article reviews the most effective Linux antivirus solutions, explains why antivirus protection is still needed on Linux servers despite the platform's inherent security, and provides detailed descriptions of each tool along with installation guidance and usage tips.
This guide explains how to use the ping utility to test connectivity, interpret bytes, time, and TTL values, and leverage advanced options like -t, -a, -n, -l, -r, as well as batch‑ping techniques for efficient network troubleshooting.
This article explains why certain Linux commands—such as rm -rf /*, overwriting partitions, moving data to /dev/null, formatting disks, fork bombs, and malicious script execution—are extremely hazardous, illustrates their destructive effects with examples, and offers practical safety recommendations to protect your system.
This article details the investigation of an unexpected native memory consumption issue in a Spring Boot service, describing how JVM and system‑level tools were used to pinpoint the leak caused by the Spring Boot loader's Inflater usage and how configuring MCC scan paths or upgrading Spring Boot eliminated the problem.
Linux futexes provide a fast userspace lock backed by a kernel wait queue, using atomic operations when uncontended and system calls such as FUTEX_WAIT, FUTEX_WAKE, and priority‑inheritance variants to manage contention, requeueing, and priority inversion via rt‑mutex structures.
This article explains how zero‑copy techniques such as DMA, sendfile, mmap and Direct I/O reduce data copies and context switches in Linux, compares their mechanisms, advantages and drawbacks, and shows typical use cases like Kafka for high‑performance I/O.
Learn how to identify and terminate Linux processes using commands like kill, killall, and pkill, including signal options, PID retrieval methods, and practical examples for both foreground and background tasks, ensuring safe and effective process management on Unix-like systems.
This article explains the evolution, principles, use cases, workflow, and limitations of eBPF, showing how programmable kernel extensions enable advanced observability, networking, and security capabilities across Linux systems and cloud‑native environments.
This article explains how Kubernetes forwards packets from the initial web request through container networking, covering the cluster's network model, Linux network namespaces, the role of the pause container, veth pairs, bridges, CNI plugins, and how services use iptables and conntrack for pod-to-pod and pod-to-service communication.
An overview of essential Linux firewall solutions—including iptables, IPCop, Shorewall, UFW, Vuurmuur, pfSense, IPFire, Smoothwall, Endian, and ConfigServer—covers their core functions, key features, and typical use cases, helping administrators choose the right tool for network protection.
This article explains why CentOS 7 is reaching end‑of‑life, reviews community and domestic alternatives such as Rocky Linux, AlmaLinux, Anolis OS, openEuler and Galaxy Kirin, and provides detailed automatic (Leapp) and manual (dnf distro‑sync) upgrade procedures with code examples for a smooth migration.
This article provides a comprehensive technical overview of DPDK, covering its architecture, core libraries, platform modules, polling and CPU‑affinity techniques, huge‑page memory management, NUMA considerations, OS tuning steps, and integration with OVS for high‑performance packet processing.
The article explains why the free command reports more memory than the available column, describes how the kernel calculates MemAvailable using min_free_kbytes and watermarks, and provides practical guidance on tuning min_free_kbytes to meet OceanBase's memory requirements.
This article summarizes a series of technical Q&A from an OSChina event covering Linux networking fundamentals such as port limits, network namespaces, TCP connection handling, C10K problem, packet loss troubleshooting, TCP memory usage, high CPU causes, useful monitoring tools, kernel parameters, and practical socket examples.
This article explains why backing up a Linux system is essential and walks you through four reliable disk‑cloning tools—dd, Partimage, Partclone, and Clonezilla—detailing installation, command usage, and best‑practice tips for creating recoverable disk images.
RedisInsight is a powerful GUI for Redis that enables monitoring, CLI interaction, and module support; this guide walks through its features, step‑by‑step installation on physical servers and Kubernetes, environment configuration, service startup, and basic usage including memory analysis and data operations.
This article compares macOS and Linux across history, kernel architecture, openness, hardware requirements, software ecosystems, user experience, customizability, gaming support, package management, and update policies, helping readers decide which platform better fits their personal or professional use cases.
This article categorizes Linux high‑risk commands, explains why a blanket ban is unsuitable, and offers practical handling, monitoring, and bastion‑host strategies to protect data across system, database, and big‑data operations.
This guide explains how Linux uses packet queuing for traffic shaping, walks through creating qdisc, class, and filter structures with tc, and shows step‑by‑step commands to limit bandwidth for specific IPs, ports, and inbound traffic using ifb devices.
The upcoming Linux 6.0 kernel hints at future Rust driver support, but significant hurdles remain such as compiler compatibility, LLVM vs GCC toolchains, and limited architecture support, making widespread Rust integration unlikely until later releases.
Amid the current tech hiring slowdown, this guide outlines a comprehensive learning roadmap for software testers, covering fundamentals, Linux, shell scripting, web fundamentals, databases, packet‑capture tools, API testing, automation frameworks, mobile testing, TestOps, and performance and security testing to help engineers stay competitive and advance their careers.
When a Linux server’s load spikes, you can quickly pinpoint CPU, memory, disk I/O, and network bottlenecks by running ten concise commands—uptime, dmesg, vmstat, mpstat, pidstat, iostat, free, sar, and top—each providing specific metrics for rapid troubleshooting.
This guide explains multiple Linux techniques—such as lscpu, /proc/cpuinfo, lshw, dmidecode, inxi, hardinfo, hwinfo, cpuid, nproc, and hwloc—to display comprehensive CPU details like model name, core count, cache sizes, architecture, and NUMA nodes, with exact commands and example outputs.
This article documents a recent Linux server compromise, detailing observed symptoms, investigative commands, discovered malicious scripts, and step‑by‑step remediation actions such as restricting SSH access, unlocking and restoring system utilities, removing malicious cron jobs, and hardening the system against future attacks.
This comprehensive guide walks you through shell scripting fundamentals—including process management, function libraries, variables, control structures, loops, debugging tools, and automation—while providing practical code examples, best‑practice tips, and visual illustrations to help both beginners and seasoned developers write robust Bash scripts.
Learn how to enhance the Linux coreutils cp and mv commands with a visual progress bar by downloading the advcpmv patch, applying it to coreutils source, compiling, installing, and creating convenient aliases, complete with example usage and performance output.
This article explains how the Linux unlink command deletes files and links, details its usage syntax, highlights its limitations—such as inability to remove multiple items or directories—and compares it with the more versatile rm command, helping you choose the right tool for safe file removal.
The article compares two interviewee types, stresses that genuine interest drives faster Linux mastery, and outlines a step‑by‑step learning path that starts with building a personal blog, then expands to monitoring, load balancing, and a comprehensive Linux operations roadmap.
This article explains the TCP keepalive mechanism, its purpose, default parameters, how to configure and verify it on Linux, its drawbacks, and the distinction between TCP keepalive and HTTP Keep-Alive, providing practical code examples and network analysis steps.
This article examines whether Linux can meet the daily development and office needs of programmers, comparing its graphical interface, development tools, communication apps, Android support, and overall advantages such as efficiency, freedom, and lower resource consumption against Windows.
This guide introduces Linux Device Tree concepts, explains why it was added to the kernel, details its syntax and standard properties, describes common nodes, and provides practical examples of OF functions for accessing nodes and properties in kernel code.
Linux employs four main I/O schedulers—NOOP, Anticipatory, Deadline, and CFQ—to manage block device request queues, balancing throughput and latency through techniques like request merging, sorting, and priority handling, with each algorithm suited to specific hardware and workload characteristics.
China announced a plan to replace Windows with Linux on over 50 million PCs, echoing Germany’s earlier shift, aiming to eliminate foreign operating systems, reduce licensing costs, and boost domestic tech, while prompting mixed reactions from hardware manufacturers and software vendors.
This guide introduces the most common Linux package management tools—dpkg, apt, rpm, yum, and dnf—explaining their purposes, supported distributions, core command‑line options, and practical examples for installing, updating, querying, and removing software packages.
This guide explains the SCSI protocol and common disk interfaces, details how to install and use the lsscsi command on various Linux distributions, describes its options and output formats, and provides examples of querying devices, interpreting results, and enabling SCSI logging for debugging.
Blackbox is a GTK4‑based Linux terminal emulator that prioritizes sleek appearance over extensive features, offering theme support, customizable UI, optional header bar, easy copy‑paste shortcuts, and straightforward Flatpak installation, while remaining in early development with occasional crashes.
This article provides a comprehensive overview of Docker's evolution, its modern architecture involving containerd, runc, and CRI, explains how containers are created and managed, and offers step‑by‑step instructions for installing, configuring, and operating containerd with the ctr command‑line tool on Linux.
This guide explains how to use Linux's TC tool to shape network traffic by creating qdisc queues, defining class hierarchies, and applying filters that bind specific IP addresses or ports to bandwidth limits, including both egress and ingress shaping via an ifb virtual interface.
This guide introduces Rsync’s core concepts, demonstrates local and remote synchronization via SSH and daemon modes, details configuration parameters, and shows how to combine Rsync with inotify‑tools for real‑time, bidirectional file replication across Linux servers.
The 2022 Chinese domestic operating system development report analyzes the current landscape of desktop and server OSes, examines industry experiences, outlines market dynamics, discusses open‑source community impacts, and forecasts future trends amid policy support and ecosystem challenges.
This article details a step‑by‑step investigation of Java service log garbled‑character problems caused by incorrect LC_CTYPE and locale settings, describing how environment variable synchronization via SSH led to ASCII encoding defaults and outlining preventive configurations for both client and server.
Linus Torvalds announced the fourth release candidate of Linux 6.0, describing it as a regular mid‑cycle test version with various bug and regression fixes, and confirming that the stable 6.0 release is on track for October.
After taking over a system via a server image, the author uncovered malicious modifications that used a ternary expression to force id=1, causing MyBatis to generate a “where 1=1” clause that deleted the entire T_QUART_DATA table, and later discovered cron jobs that removed core jars, illustrating a thorough forensic debugging process.
This guide explains Linux traffic control fundamentals, showing how to create qdisc, class, and filter structures with the tc tool to shape traffic, limit bandwidth for specific IPs or ports, and manage both egress and ingress traffic using ifb devices.
This guide shows how to use iptables to allow only a designated IP address to access a host's port 80, how to apply the same restriction to Docker containers by adding rules to the DOCKER-USER chain, and how to make the settings persistent across reboots.
This article explains how TCP connections behave when any of the three-way handshake or four-way termination packets are lost, detailing the kernel‑controlled retransmission mechanisms, timeout intervals, relevant sysctl parameters, and the exact sequence of events for each loss scenario.
This guide explains the purpose of the Linux cheat utility, compares it with man and info, shows how to install both the Go and Bash versions, and provides detailed usage examples, configuration tips, and ways to extend its cheat sheets for faster command reference.
This article provides a comprehensive guide to diagnosing and fixing a wide range of Docker problems, including storage migration, disk space shortages, missing libraries, container corruption, network configuration, permission errors, image management, and timeout issues, with detailed command-line solutions and configuration examples.
This guide explains how to identify and troubleshoot TCP throughput limitations by examining sender, receiver, and network bottlenecks, understanding rwnd and cwnd values, using Linux tools like ss and Wireshark, and interpreting packet traces to pinpoint congestion or loss.
This guide explains why TCP throughput may fall short of network capacity, covering sender, receiver, and network bottlenecks, how to read receiver window (rwnd) and congestion window (cwnd) values on Linux, and how to interpret Wireshark graphs to pinpoint the root cause.
This article explains the four Linux kernel I/O schedulers—NOOP, Anticipatory, Deadline, and CFQ—covering their design goals, how they manage request queues through merging and sorting, and when each scheduler is best suited for different storage hardware and workloads.
This guide walks you through installing Git, creating a dedicated git user, configuring SSH keys, preparing a repository directory, initializing a bare repository, and applying essential security hardening to run a private Git server on a Linux machine.
This guide walks through configuring a remote Linux machine for Go development using VS Code’s Remote‑SSH extension, covering SSH key setup, host configuration, Go installation, VS Code extensions, and additional system tweaks to create a fast, resource‑rich development environment.
In high‑concurrency scenarios, massive TIME_WAIT TCP connections can exhaust local ports, causing new connections to fail, but by understanding the TCP four‑handshake, adjusting socket reuse settings, and using keep‑alive, you can mitigate the issue.
This guide surveys more than a dozen Linux command‑line utilities—including nethogs, nload, iftop, slurm, netstat, and many others—explaining their unique features, typical use cases, and installation commands so administrators can effectively monitor bandwidth, connections, and overall network health.
This article explains Netty’s high‑performance asynchronous architecture, the evolution of I/O multiplexing models from select to poll and epoll, demonstrates Java‑C integration via JNI with detailed code examples, and provides a complete hand‑written epoll server in C for achieving million‑connection concurrency.
This guide walks you through eight practical steps to secure SSH on a Linux server, including disabling root login, changing the default port, restricting empty passwords, limiting authentication attempts, enforcing protocol 2, disabling forwarding, using key‑based authentication, and applying IP‑based access controls.
This guide explains Linux file system paths, covering the definition of absolute and relative paths, how slashes work, practical command examples, the special '.' and '..' notations, and when to choose each approach for everyday command‑line and scripting tasks.
The article explores Linux’s origins, the development of its various distributions, and explains why many governments worldwide prefer Linux desktop systems due to its open‑source nature, extensive software ecosystem, portability, stability, security, and broad protocol support, despite its modest market share.
This article explains the fundamental concepts of Linux processes, their relationship to programs, threads, kernels, and memory, details the internal task_struct implementation, and walks through the full lifecycle from creation with fork, loading via execve, execution, and termination including exit_group and zombie handling.
This article introduces MinIO, a high‑performance, GNU‑AGPL‑licensed object storage compatible with Amazon S3, explains its core concepts such as buckets, drives, sets and erasure coding, and provides a detailed step‑by‑step guide for deploying a distributed MinIO cluster on Linux, including configuration, systemd service setup, Nginx load balancing, and client (mc) usage.
Learn the essential Linux disk I/O performance metrics—utilization, saturation, IOPS, throughput, and response time—and discover how to monitor them using iostat, pidstat, and iotop, with practical examples and guidance for interpreting /proc/diskstats data and evaluating storage bottlenecks.
The article explains how Paragon Software’s NTFS3 Linux kernel driver, after months of inactivity and a delayed code submission, finally reached Linus Torvalds’ attention post‑merge‑window, prompting an exception to merge it while emphasizing the importance of timely contributions.
This article explains the mmap system call’s core concepts, mapping process, kernel mechanisms, differences from traditional file I/O, performance benefits, and practical usage details, helping readers understand how memory‑mapped files work in Linux and why they’re advantageous for high‑performance applications.
This guide walks you through checking disk usage, adding a new disk, creating a physical volume, extending the volume group and logical volume, and finally growing the XFS filesystem to successfully enlarge the Linux root partition.
This guide explains what CPU context switches are, how to monitor them with vmstat and pidstat, analyzes a sysbench‑generated load case, examines interrupt sources, and provides practical thresholds and troubleshooting steps to improve Linux system performance.
This article explores the practicality of Linux by examining its graphical interface, development environment support, communication tools, ability to replace Windows, Android app compatibility, and the broader benefits of openness, efficiency, and customization that make it a compelling operating system choice.
This article explains how hardware architecture, Linux OS version, kernel configuration, OVS integration, memory management, NUMA awareness, and CPU micro‑architecture affect DPDK application performance and provides concrete tuning steps such as CPU isolation, service disabling, huge‑page setup, and optimized memory allocation.
This guide explains how to view Docker and Kubernetes container exit codes, lists the most common codes such as 0, 1, 137, 139, and 143, describes what each code means, and shows the commands and scenarios that generate them.
This article reviews the Ubuntu 22.04.1 releases of three official flavors—Unity, Cinnamon, and the China‑focused Kylin—detailing their desktop features, resource usage, and how they differ from the main Ubuntu distribution.
Learn step‑by‑step how to enlarge a Linux root filesystem using LVM commands—checking disk usage, creating a physical volume, extending the volume group and logical volume, and resizing the XFS filesystem—complete with command examples and verification screenshots.
This guide walks you through a complete Linux incident‑response workflow—identifying suspicious behavior, locating and terminating malicious processes, eliminating virus files, closing persistence mechanisms, and hardening the system to prevent future compromises—using practical shell commands and real‑world examples.
This guide presents a concise collection of essential Linux command‑line tools, explaining their purpose and basic usage with examples, helping newcomers quickly perform common tasks such as navigating directories, managing files, monitoring system resources, and controlling processes.
This article explains how to assess Linux system performance by examining CPU usage with top, interpreting load averages, using vmstat for detailed metrics, monitoring memory consumption via top, understanding cache behavior, evaluating I/O performance with iostat and sar, and provides practical commands and visual examples for each component.
This article explains the Linux unlink command, how it deletes files and links, its syntax, limitations compared with rm, and scenarios where using unlink is preferable, providing clear examples and safety considerations for system administrators.
This guide introduces a curated list of Linux command‑line utilities—including nethogs, nload, slurm, iftop, collectl, netstat, and many others—explaining their purpose, installation commands for various distributions, and basic usage examples to help system administrators monitor network traffic and bandwidth effectively.
This guide explains why the su command is available to all users by default, then shows how to back up the sudoers file, edit it with visudo, define a command alias to disable /usr/bin/su, and apply the restriction to individual users or entire groups, complete with verification steps.
This article introduces a curated list of Linux command-line utilities—including nethogs, nload, iftop, slurm, netstat, and more—explaining their unique features, typical use cases, and installation commands to help system administrators and developers effectively monitor network traffic and bandwidth.
This article presents a comprehensive list of twelve Linux commands and graphical tools—including /proc/meminfo, atop, free, GNOME System Monitor, htop, KDE System Monitor, memstat, nmon, ps, smem, top, and vmstat—that allow you to view and analyze memory consumption in real time, with usage examples and screenshots.
This guide introduces eight powerful Linux commands—rsync, screen/tmux, lsof, python -m, vimdiff, nc, date, and systemctl—explaining their key options, typical use‑cases, and providing ready‑to‑run examples that help you work faster and smarter on the command line.
This article explains how to interpret the Linux free command output, clarifies the roles of total, used, free, shared, buffers, and cached memory, describes the -/+ buffers/cache values, and provides commands for manually clearing swap and cache.
