This guide walks through the complete GCC compilation pipeline—preprocessing, compilation, assembly, and linking—demonstrates how to build a simple C program, inspect the resulting ELF file, and use Binutils tools to analyze sections and disassemble the binary.
This article presents a curated collection of Bash scripts that automate key Linux operations such as MySQL replication monitoring, directory change detection, bulk user creation, website health checks, remote command execution, one‑click LNMP deployment, resource usage reporting, high‑resource process identification, and automated Java and PHP project deployment.
At the 2024 OpenSource Summit China in Hong Kong, Linus Torvalds and Dirk Hohndel discussed the Linux kernel’s development roadmap, release cadence, security practices, the slow adoption of Rust, and the potential role of AI, while sharing candid views on cloud, Kubernetes, and legacy kernel support.
This guide explains why IPv6 is essential, outlines its key benefits, and provides a detailed, step‑by‑step process for checking support, editing Netplan or interfaces files, adding a static IPv6 address, applying changes, and verifying the configuration on Ubuntu systems.
This guide introduces Linux process‑monitoring tools—ps, dstat, top, and htop—by likening them to the four legendary detectives, explains their options, output fields, and usage examples, and provides visual references to help readers understand and effectively track system resources.
A recent incident with systemd‑tmpfiles – triggered by the ‑‑purge option in version 256 – caused unexpected deletion of files in /home, prompting a heated discussion among developers, a GitHub issue, and a rapid patch that clarified the command’s scope and added safeguards.
The article examines the role of various locks in Linux kernel memory management, explains their APIs and sleeping constraints, presents detailed case studies of lock‑related performance patches—including per‑memcg LRU, mmap_lock IO‑fault path, SPF, PVL, fault‑around, unmap, and rmap lockless optimizations—and summarizes common strategies for reducing lock contention and improving scalability.
This guide walks through checking the OS architecture, preparing the environment, downloading the appropriate MySQL 5.7 packages for ARM, installing and configuring MySQL, setting up automatic startup and environment variables, initializing the server, securing the root account, and finally configuring master‑slave replication between two servers.
Learn how to monitor and test network performance in Linux using five powerful command‑line utilities—nethogs for per‑process bandwidth, nload for real‑time traffic graphs, cbm for colorful interface, iftop for host‑level connections, and iPerf for detailed throughput measurements.
This guide shows how to install and run the Chinese AAA title Black Myth: Wukong on deepin 23, covering NVIDIA driver fixes, Steam installation, Proton configuration, system requirements, download methods, and performance screenshots.
This article explains how high‑level C/C++ programs are transformed into processor‑executable binary code on Linux, covering preprocessing, compilation, assembly, linking, the GCC toolchain, Binutils utilities, C runtime libraries, and ELF file analysis with practical command examples.
This article shares ten practical operations strategies—including change rollbacks, safe handling of destructive commands, prompt customization, rigorous backup and verification, production environment discipline, careful handovers, robust alerting, cautious automatic failover, meticulous checks, and simplicity—to dramatically improve system reliability and availability.
Embedded Linux systems often auto‑start applications after boot to save resources, and this guide explains three methods—using a /linuxrc script, adding scripts under /etc/init.d, and editing /etc/rc.d/rc.local—plus a detailed overview of Linux runlevels and the complete boot sequence.
This guide explains how to configure Linux routing by adding host, network, and default routes with the route command, detailing the command syntax, example commands, route table fields, and how to delete routes when they are no longer needed.
This tutorial explains why you cannot run fsck on a mounted root filesystem, shows how to inspect the last check with tune2fs, and provides a step‑by‑step method using a /forcefsck file to force a root filesystem check on the next reboot.
This guide explains Linux file linking concepts—including soft, hard, and symbolic links—detailing how to create, inspect, and remove them with commands like ln, ls, touch, cat, rm, and unlink, while highlighting inode behavior and directory restrictions.
This article shares ten practical operations strategies—ranging from change‑rollback procedures and cautious handling of destructive commands to robust backup verification, alerting, and meticulous hand‑over practices—that together help teams dramatically reduce system outages and maintain high availability.
This tutorial walks through installing FastDFS on a Linux server, configuring its tracker and storage nodes, integrating it with Nginx via the FastDFS‑nginx module, and exposing the service publicly using the cpolar tunneling tool, providing complete commands and configuration snippets for each step.
Learn what rsync is, how to compile it for an ARM‑based development board, configure the build to disable SIMD and other features, install the binary, and use rsync commands with common options to efficiently synchronize files between the board and a PC.
This article presents a practical guide for backend developers to troubleshoot Linux performance problems, covering essential analysis tools, a systematic diagnosis method, and detailed checklists for CPU, memory, disk I/O, and network I/O issues.
This guide explains how to use the powerful lsof command to list information about files opened by processes, filter results by file type, user, process name, directory, network connections, and even repeatedly monitor changes, providing practical examples and code snippets for Linux administrators.
This guide walks you through identifying a CPU‑mining malware infection on a Linux server, from spotting abnormal CPU usage with top, tracing the malicious executable, disabling its cron job, and safely cleaning the infected files and processes.
This guide introduces ShellCheck, a static analysis tool for Linux shell scripts, explains its key features, provides step‑by‑step installation commands for various distributions, demonstrates usage with example scripts and output, and shows how to integrate it into popular editors.
This guide walks through creating a ZFS filesystem from a pool, setting quotas and reservations, configuring an alternate mount point, enabling compression, and verifying compression effectiveness, helping Linux users save disk space with ZFS.
Learn how Linux’s powerful text-processing tools—pipes, grep, sed, and awk—work together to filter, transform, and analyze data, with clear syntax explanations, practical examples, and essential tips for chaining commands, handling output, and avoiding common pitfalls.
Learn step‑by‑step how to configure iptables to log both inbound and outbound dropped packets to syslog, customize log prefixes and levels, and interpret the resulting log entries for effective firewall troubleshooting on Linux systems.
This article demystifies the Linux free command’s “buffers” and “cached” fields by tracing their origins through /proc/meminfo, kernel source functions such as meminfo_proc_show, nr_blockdev_pages, and page‑cache mechanisms, and demonstrates the differences with practical experiments.
This comprehensive guide explains the Linux find utility, covering its basic syntax, expression structure, operators, options, tests, actions, and advanced usage examples to help users perform precise and efficient file‑system searches.
This guide walks you through preparing the environment, installing iPerf on Windows or Linux servers, running it in server and client modes, testing TCP and UDP performance, measuring latency with ping, and checking all available options to ensure reliable network bandwidth and latency measurements.
This guide introduces Docker’s fundamental concepts, explains its advantages and architecture, walks through installation steps, and provides a comprehensive list of common Docker commands for managing images and containers, including practical examples such as setting up SSH access within a container.
This article explains Linux I/O schedulers, compares the noop, cfq, and deadline algorithms, shows how to view and modify them on CentOS 6/7, and presents benchmark results indicating that the noop scheduler delivers the best performance on SSDs for MySQL workloads.
This guide explains how to use Nmap on Linux to perform simple, single‑port, full‑range, and custom port scans, interpret common port states, and understand typical service ports for effective network security testing.
A newly disclosed Linux kernel vulnerability called "indler"—a 0‑day memory‑corruption bug hidden since 2012—was uncovered by security researcher Zhang Yinkui, who detailed its discovery via a random kernel oops, KASAN detection, and its potential for massive remote code execution across billions of devices.
This article provides a comprehensive, step‑by‑step guide to the most important native Linux networking commands—such as hostname, host, ping, curl, ip, ss, traceroute, dig, and tcpdump—explaining their purpose, common usage examples, and key options for effective system and network troubleshooting.
This guide explains Linux permission basics, the special SUID/SGID/sticky bits, and shows how to use the powerful find command to locate files by name, timestamps, size, or exact permissions, complete with practical code examples.
This guide explains how to install the nslookup tool on various Linux distributions and demonstrates seven common usages—including querying IP addresses, specifying DNS servers, retrieving specific record types, performing reverse lookups, setting search domains, using interactive set commands, and exiting the tool—to help diagnose DNS issues effectively.
This guide explains how to use static-php-cli to compile a self‑contained PHP CLI binary for Linux and macOS, covering supported platforms, required PHP versions, environment preparation, dependency download, build commands, verification, packaging, and multi‑version management.
This guide explains how to encrypt a shell script using gzexe, covering script preparation, making it executable, running gzexe to produce an encrypted file, verifying and executing the encrypted script, and optionally decrypting it, plus installation instructions for gzexe on Debian and Red Hat systems.
This guide explains how to install the traceroute network diagnostic tool on various Linux distributions, shows the basic command syntax and common usage examples, and details both standard and advanced options for customizing trace routes, while highlighting important precautions.
This comprehensive guide explains Nginx's high‑performance architecture, module system, multi‑process model, FastCGI integration, configuration best practices, tuning techniques, error troubleshooting, and a known PHP‑related vulnerability, providing practical steps for optimal deployment on Linux servers.
This guide walks through the most common Linux file‑viewing commands—cat, tac, head, tail, more, and less—detailing their purpose, syntax, useful options, arguments, and practical examples to help you navigate and inspect file contents efficiently.
This comprehensive guide walks you through the fundamentals of Linux shell scripting, covering why it matters, essential prerequisites, variable handling, string manipulation, arithmetic operations, condition testing, control structures like if/else, for/while loops, functions, case statements, and array usage, all with clear examples and practical code snippets.
This tutorial walks you through downloading the openEuler ISO, setting up a VMware Workstation virtual machine, performing a custom installation with manual partitioning, configuring network settings, installing essential tools, and verifying the system after migration from CentOS.
This step‑by‑step guide shows how to install OpenVPN on a public‑cloud Linux host, generate CA and server certificates with Easy RSA, configure the OpenVPN server, create a user authentication script, and set up matching client configurations for secure VPN access.
This guide walks you through installing NTP, configuring server and client settings, applying security restrictions, adding a local clock backup, logging, and verifying synchronization to keep Linux systems accurately timed across a network.
This guide walks through the most common Linux compression and archiving tools—zip, unzip, rar, unrar, and tar—detailing file formats, command syntax, options for compression levels, encryption, and extraction, plus practical examples for each utility.
This article examines mmap's historical origins, its performance benefits and drawbacks, and analyzes how Prometheus' time‑series database employs memory‑mapped files, revealing why mmap does not degrade Prometheus performance despite known kernel‑level issues such as TLB misses and lock contention.
This article introduces a new book 'Deep Understanding of Linux Processes and Memory' that systematically explains CPU, memory, and process scheduling principles, covering hardware fundamentals, virtual memory, Golang coroutines, container resource management, and performance optimization techniques.
This article explains how Linux creates processes using fork, vfork, clone and pthread_create, reveals the role of the init process, explores clone flags and namespace checks in the kernel, and shows why understanding these fundamentals demystifies container startup.
This guide explains how to use the Linux date command to display, format, and manipulate dates and times, covering options such as –date, –file, –set, –u, –r, relative dates, and custom format strings, with practical code examples for each scenario.
This article explains hyper‑threading fundamentals, distinguishes physical, logical, and CPU cores, shows how to query CPU topology on Linux, introduces the concept of CPU affinity, demonstrates using the taskset command and related syscalls, and provides C API examples for setting process and thread affinity.
This article presents ten hands‑on examples of using the Linux fsck utility—including checking specific partitions, employing options like -A, -t, -M, -y, -n, and -a—to detect, report, and automatically fix filesystem errors while explaining exit codes and best‑practice recommendations.
This comprehensive guide explains how to use the Linux lsof command to list information about open files, directories, sockets, and devices across processes, covering options for filtering by file, process, user, network connections, and advanced features like repeat mode and combined queries.
This guide walks you through obtaining the Linux kernel source, configuring key options, compiling and installing the kernel, tuning sysctl parameters, and continuously monitoring system metrics to achieve higher performance, stability, and security in high‑load environments.
This guide explains how to create a high‑availability web load‑balancing cluster using Linux Virtual Server (LVS) and Keepalived on CentOS, covering background, terminology, environment setup, detailed configuration steps for master and backup nodes, real‑server preparation, HA testing, and final conclusions.
This guide walks you through checking the current partition layout, safely unmounting the volume, using fdisk to delete and recreate the partition with the same start sector, resizing the ext4 filesystem, remounting the disk, and configuring automatic mounts via fstab, systemd, or autofs.
This article presents a Bash script that gathers comprehensive Linux system metrics—including CPU core count, utilization percentages, context switches, interrupts, load averages, memory and swap usage, and disk I/O statistics—explaining each command and its purpose for effective server monitoring.
This guide explains what RabbitMQ is, walks through installing Erlang and RabbitMQ on a Linux system, shows how to start and verify the server, and provides troubleshooting tips for common startup errors such as port conflicts.
The article presents a concise mind‑map of essential Linux performance tools and a flexible troubleshooting workflow, guiding backend developers through CPU, memory, disk, and network issues by using utilities such as top, oprofile, slabtop, iotop, netstat, and strace to quickly pinpoint and resolve bottlenecks.
This guide walks through the most frequently used Ansible modules—including file, copy, yum_repository, yum, service, systemd, user, group, fetch, get_url, and setup—explaining their key options and demonstrating ad‑hoc command usage with complete code examples for Linux automation.
Learn how to use the Linux cut command for powerful text processing, including selecting character columns, ranges, specific fields with delimiters, complementing fields, changing output delimiters, and combining cut with other Unix tools such as grep, sed, and ps.
This tutorial explains what a VPN is, outlines its two main types, introduces OpenVPN, and provides detailed, command‑line instructions for installing, configuring, and testing both the OpenVPN server and client on a Linux environment.
This guide explains how to bind two network interfaces into a single virtual NIC on Linux using the bonding driver, covering supported modes, detailed configuration files, command-line steps, verification commands, and practical tips for ensuring high‑availability without IP duplication.
This guide shows how to create a Bash script that backs up a specific MySQL database using mysqldump, compresses the dump, automatically deletes old backups, explains the find -mtime option, and schedules the process with cron, plus detailed steps for restoring the data.
This article compiles 19 practical Linux, security, networking, and Python interview questions covering command‑line techniques, system monitoring, load‑balancing, HTTP protocols, common vulnerabilities, TCP handshakes, TIME_WAIT optimization, and code snippets to help candidates prepare for sysadmin roles.
This guide explains how to configure additional routing tables and policy‑based routes on a Linux server with two network interfaces, covering IP address inspection, routing table edits, ip rule commands, and persistence across reboots.
A practical guide explains how to use top, iostat, netstat, df, du and other common Linux commands to monitor CPU, memory, disk, and network status, interpret their output, and troubleshoot performance problems in production environments.
This comprehensive guide explains Linux permission fundamentals, user and group management, file permission modes, special bits like SUID, SGID and Sticky, hidden attributes with chattr/lsattr, ACL configuration, and privilege escalation using su and sudo, complete with practical command examples.
This article provides a comprehensive overview of Nginx’s high‑performance features, module architecture, process and I/O models, FastCGI integration with PHP‑FPM, configuration best practices, tuning techniques, and common error troubleshooting, offering practical guidance for optimizing and securing Nginx deployments.
This article compiles several Zhihu users' candid accounts of a typical Linux operations day, highlighting constant interruptions, emergency firefighting, performance tuning, monitoring, tool development, and a balanced time‑allocation strategy to make ops work more efficient and sustainable.
This article explains how to configure Docker and Containerd to use domestic image‑mirror services, providing detailed commands and verification steps that dramatically reduce image‑pull latency and improve development and operations efficiency in cloud‑native environments.
This article introduces Supervisor, a client‑server process monitoring tool for Unix-like systems, explains why it solves persistent process deployment issues, walks through installation, configuration, command‑line usage, advanced features such as process groups and auto‑restart policies, and provides code examples for practical implementation.
Learn how to install and use the Linux traceroute utility across Debian/Ubuntu and CentOS/RHEL systems, understand its basic syntax, explore common and advanced options, and see practical examples for network path diagnostics and troubleshooting.
This article explains what disks are, compares mechanical HDDs and SSDs, describes disk I/O concepts, outlines key performance metrics such as IOPS, throughput, utilization and latency, and introduces Linux tools like iostat, iotop, sar for monitoring and analyzing storage performance.
This guide explains how to install, use, and interpret the Linux route command for displaying and manipulating the kernel IP routing table, covering options, output fields, persistence tricks, and practical examples for querying, adding, deleting, and rejecting routes.
Version 1.2 of the Linux Emergency Handbook introduces critical updates such as SSH key backdoor checks, detailed command timestamp logs, new journalctl log viewing techniques, enhanced password checks, added data USB guidance, and revamped post‑incident stages including routine security checks, loss assessment, and targeted investigations.
This article defines Linux distributions, explains how they build on the open‑source kernel, and reviews ten popular distros—Linux Mint, Manjaro, openSUSE Leap, Elementary OS, Ubuntu, Fedora, Zorin OS, Debian, Pop!_OS, and MX Linux—highlighting each one's key features and ideal use cases.
This guide walks through SSH secure tunneling techniques—including local, remote, and dynamic (SOCKS) port forwarding—detailing command syntax, option effects, binding addresses, and practical examples for accessing otherwise unreachable services across network boundaries.
This guide walks you through expanding a Linux block device from 500 GB to 2 TB, adjusting the partition table with fdisk, resizing ext4 filesystems, remounting the volume, and configuring persistent or on‑demand mounts via fstab, rc.local, systemd, and autofs.
The article traces Azure’s evolution from a Windows‑only cloud to a platform that tests over a thousand Linux distributions monthly, detailing its Linux guest OS lifecycle, certification process, and the automated testing framework that ensures seamless large‑scale Linux operations on Azure.
This guide walks through a real‑world operations scenario, showing how to write and run a Bash script that uses the sort command with numeric and field options to correctly order a list of IP addresses for easier log analysis and network troubleshooting.
This guide explains how to declare, initialize, access, modify, iterate, measure length, and delete Bash arrays, and demonstrates practical scenarios such as file list handling, argument passing, and numeric calculations to boost script efficiency.
Virtio, the Linux standard I/O virtualization framework, uses a semi‑virtualized front‑end driver and back‑end device linked by virtqueues, works across hypervisors (e.g., QEMU/KVM) via PCI or MMIO, enabling high‑performance, low‑overhead device emulation—as illustrated by the virtio‑snd driver—while supporting cloud and Android virtualization scenarios.
This guide walks through practical Linux security hardening on RHEL7, covering TCSEC security levels, account lockdown, password policies, SSH hardening, SELinux activation, firewall minimization, immutable system files, and other configuration tweaks to raise the system to a B1 security rating.
This guide explains how to use Linux commands like df, du, find, lsof, and tune2fs to locate large directories, uncover deleted files that still occupy space, and adjust reserved root space, enabling you to resolve unexpected disk‑usage alerts efficiently.
Learn step-by-step how to prepare your Linux server, download and install Docker 20.10.24 manually, configure daemon settings, set up systemd service, start and verify the engine, and apply essential security and optimization practices for reliable production deployments.
This guide walks you through preparing a Ceph cluster, enabling the NFS module, creating an NFS service with nfs‑ganesha, exporting a CephFS share, mounting it from a client, and configuring high‑availability using haproxy and keepalived.
This guide shows how to set up a Ubuntu server and a CentOS client, install hping3 and netcat, and use them to reliably detect whether specific UDP ports are open or closed, interpreting packet loss, ICMP Port Unreachable, and connection refusal messages.
This guide explains the concept of Linux user namespaces, how they isolate UID/GID for Docker containers, the required subuid/subgid mappings, step‑by‑step daemon configuration, verification commands, and known limitations when using user namespace isolation.
This guide introduces five open‑source Linux utilities—NetHogs, nload, CBM, iftop, and iPerf—explaining their focus, usage commands, and how they help monitor process‑level bandwidth, interface traffic, and overall network performance in production settings.
This article provides an extensive collection of Linux command-line utilities covering system information, file management, networking, package handling, backup, and more, serving as a practical reference for developers and system administrators in daily operations.
This guide explains why zombie processes appear in Linux, demonstrates how to reproduce them with sample code, shows how to identify them using ps, discusses the system risks they pose, and provides proper cleanup techniques using wait/waitpid and parent termination.
The article traces Neofetch’s rise as a customizable Linux system‑info tool, details the sudden disappearance of its creator Dylan Araps, explains the 2024 repository archival with a farming note, and reviews emerging alternatives while reflecting on a broader trend of developers leaving tech for agriculture.
This guide explains the Linux /proc virtual file system, details the special role of /proc/self for accessing the current process's data, and provides command examples for retrieving cmdline, cwd, exe, environ, maps, and mem information.
When a VMware VM with a 200 GB system disk runs an 11 GB Docker service, it may report ‘no space left on device’ because the LVM logical volume for /var is only 1 GB, and the guide shows how to extend the relevant LVM volumes and resize the filesystems to resolve the issue.
This guide explains how to install the net-tools package, use the Linux route command to view the kernel IP routing table, add or delete static routes, make routes persistent, and interpret the output fields with practical examples.
This guide explains how to install the net-tools package, use the Linux route command to display the kernel IP routing table, and perform common operations such as adding, deleting, and rejecting routes with detailed option descriptions and practical examples.
This guide explains how to use the ssh -Q command to list all OpenSSH-supported ciphers, cipher‑auth methods, key‑exchange algorithms, public‑key types, certificate keys, MACs, protocol versions, and signature algorithms, providing concrete command output and common examples for each category.
This article provides a comprehensive guide to optimizing Kunpeng‑based servers, covering hardware characteristics, matrix multiplication benchmarks, Von Neumann architecture insights, soft and hard acceleration, compiler and JDK tweaks, NUMA tuning, Nginx and OpenSSL acceleration, disk and network optimizations, application‑level tuning, and a step‑by‑step MariaDB performance‑tuning checklist.
This article explains Linux's memory management architecture, covering physical memory organization, the buddy and SLUB allocators, virtual address spaces for user and kernel, page‑table translation, TLB caching, and the role of swap in virtual memory.
