This guide explains how to monitor memory usage on Linux servers, identify common causes of sudden memory consumption such as leaks, stuck processes, or high load, and provides concrete commands and remediation steps to stabilize system performance.
This guide walks through practical Linux command-line techniques—including generating file checksums, locating files quickly, editing long commands, inspecting and managing processes, capturing terminal output, examining binary dependencies, and using various text‑viewing utilities—to boost everyday system administration efficiency.
This article presents a curated list of twenty practical Linux command‑line tricks—from tab completion and directory navigation to command chaining, history search, log monitoring, and useful shortcuts—that help both beginners and seasoned users work faster and avoid common pitfalls.
This article introduces eBPF fundamentals, explains the Compile‑Once‑Run‑Everywhere (CO‑RE) approach, compares it with traditional eBPF, outlines best practices, and walks through a complete Go‑based example using the Cilium/eBPF library and the eunomia‑bpf runtime.
This guide explains cURL’s command‑line syntax, common options, error codes, and demonstrates how to build a C program that monitors a log file, creates timestamped backups, and automatically uploads them to an FTP server using cURL.
This guide explains the concept of Linux loop devices, shows how to create and mount a file as a virtual block device using both the simple mount -o loop method and the explicit losetup approach, and dives into the kernel implementation and typical use cases.
This guide walks through the purpose, advantages, required Linux packages, Go libraries, exact installation commands, and version details needed to set up a functional eBPF development environment on an Ubuntu system, while explaining each step’s rationale.
This guide introduces two open‑source shell scripts—CentOS_Check_Script and CentOS_Protective_Script—designed to enforce security hardening on Red Hat/CentOS systems, covering password policies, audit log protection, user management, and various security controls, with usage instructions and download links.
This guide walks through the step‑by‑step process of downloading, compiling, and enabling the MongoDB extension for PHP on a Linux server, covering both online and offline installation methods and how to verify the extension is loaded successfully.
An in‑depth post‑mortem of a recurring midnight kernel panic caused by a malformed sk_buff structure, detailing how vmcore analysis, packet inspection, and netfilter hook tracing pinpointed a third‑party module bug in Linux 5.10, and outlining remediation steps.
When a data platform server suddenly shows CPU utilization near 99% despite modest traffic, this guide walks through pinpointing the offending Java process, tracing the high‑load thread, uncovering a time‑conversion routine that over‑calculates seconds, and applying a lightweight fix that drops CPU load by dozens of times.
This guide walks through creating partitions, mounting devices and filesystems using the Linux mount command, exploring common scenarios such as mounting CD-ROMs, viewing current mounts, binding directories, remounting, mounting ISO images, and safely unmounting with options like lazy, force, and selective unmounting.
This article compiles ten practical operations‑engineer guidelines—ranging from change rollbacks and safe command aliases to backup verification, monitoring, and cautious automated failover—to help maintain high availability and avoid costly production incidents.
This article walks through creating a first eBPF program using C and Go on Ubuntu 22.04, covering required dependencies, kernel‑space vs user‑space concepts, event selection, BPF map definition, and a tracepoint function that measures per‑process CPU time.
This article explains the Linux kernel device driver model introduced in 2.6, how devices, buses, classes and drivers are represented, how the sysfs virtual filesystem exposes their hierarchy, and walks through the registration and matching process for platform buses, drivers, and devices with detailed code examples.
This guide explains how to prepare source and target servers, install iPerf, run it in server and client modes on Windows (or Linux), and use specific commands to measure TCP bandwidth, UDP jitter, packet loss, and network latency, including required firewall and security‑group settings.
Learn how to accelerate Docker image pulls by configuring registry mirrors, then follow step‑by‑step instructions to pull, run, inspect, and manage Nginx containers, including commands for starting, stopping, logging, networking, and modifying container files, ensuring efficient container operations.
This comprehensive guide walks IT and DevOps professionals through understanding ARM and x86 architectures, setting up the build environment, creating and customizing base images, optimizing size and performance, and packaging for distribution, with practical commands and best‑practice recommendations.
This guide walks through comprehensive Linux security hardening on RHEL7, covering account lockout, password policies, SELinux configuration, SSH port changes, root login disabling, umask restriction, immutable system files, GCC limitation, log protection, minimal firewall rules, and related command examples.
The article explains how Linux separates board‑level information from drivers using a bus‑device‑driver model, illustrating high cohesion and low coupling with concrete code examples, matching mechanisms, and the evolution toward device trees for scalable hardware abstraction.
This guide explains Linux's traditional permission model, introduces Access Control Lists (ACL) and the crucial mask concept, shows how to view and modify ACLs with getfacl/setfacl, and provides practical examples for correctly configuring file permissions.
This comprehensive guide explains DNS fundamentals, Linux client configuration, BIND9 server setup, advanced features like DNSSEC and DoH, and essential troubleshooting and security practices, empowering system administrators and network engineers to manage and secure DNS services effectively.
This guide introduces tcpdump, a powerful command‑line packet analyzer, covering its history, core features, basic usage, advanced filtering techniques, practical tips, and real‑world scenarios to help system administrators and network engineers diagnose and monitor network issues effectively.
This article walks through a production‑level OceanBase connection‑timeout incident, detailing how to examine OBProxy logs, capture and analyze network packets with tcpdump and Wireshark, identify a blocked random port, and apply kernel‑parameter fixes to prevent the issue.
Learn how to enable and configure IPv6 on Ubuntu, covering its benefits, checking interface support, editing Netplan or legacy network files, setting static addresses, applying changes, and verifying the configuration with practical command examples.
Celebrating Linux’s 33rd birthday, this article traces its humble 1991 beginnings as Linus Torvalds’s “small hobby” to its ubiquitous presence today across desktops, servers, mobile devices, supercomputers, and even the International Space Station, highlighting its profound impact on modern computing.
This guide explains how to use the dd command to clone an Ubuntu system disk to another drive or an image file, covering prerequisites, preparation steps, backup and restore commands, optional compression, advantages, drawbacks, use cases, and important precautions.
This article traces the origins and evolution of CentOS, explains the shift to CentOS Stream, outlines the end‑of‑life schedule for CentOS Linux 7 and 8, and evaluates a range of alternative Linux distributions and domestic operating systems for enterprises seeking a replacement.
This article explains what swap space is, why it matters for system stability and performance, and provides detailed Linux commands and procedures for creating, configuring, activating, and monitoring swap files or partitions.
Zero‑copy techniques such as mmap + write, sendfile, and sendfile + DMA scatter/gather reduce CPU‑memory copies and context switches compared with traditional read/write IO, improving performance for high‑throughput systems like RocketMQ and Kafka, while explaining user‑kernel mode, DMA, and their trade‑offs.
This guide presents twenty practical Linux command‑line shortcuts—including tab completion, directory navigation, command chaining, history search, log monitoring, and alias creation—that help both beginners and experienced users work faster and avoid common pitfalls.
WebVM is an open‑source project that lets you launch a complete Linux virtual machine inside a web browser, supporting multiple programming languages and enabling deployment via GitHub Pages without any local installation.
This comprehensive guide explains why Linux system monitoring is crucial, outlines key metrics such as CPU, memory, disk I/O, network, and process usage, recommends essential command‑line tools, and provides advanced techniques, automation scripts, best practices, and common pitfalls to ensure reliable, secure server performance.
Learn the differences between Source NAT (SNAT) and Destination NAT (DNAT), their definitions, mechanisms, key use cases such as address sharing, load balancing, and security, and follow step‑by‑step iptables examples to configure these NAT rules in a typical network scenario.
This tutorial explains Linux Logical Volume Manager (LVM) fundamentals, walks through creating and removing physical volumes, building and deleting volume groups, provisioning logical volumes, formatting and mounting them, and performing size extensions, reductions, and snapshot operations with concrete command examples.
This guide explains how to configure additional routing rules for a second network interface on Linux by creating a new policy routing table, adding specific routes and rules with iproute2 commands, and verifying that traffic uses the intended NIC.
This guide explains practical commands like du, find, and lsof to locate large directories or deleted files consuming disk space, and shows how to adjust reserved filesystem space with tune2fs to reclaim lost capacity.
This guide explains the purpose of common Linux log files, how syslog and klogd collect system and kernel messages, the structure of syslog entries, configuration of /etc/rsyslog.conf for both receiving and forwarding logs, and how to manage log rotation with logrotate.
Learn how to use Linux process-monitoring tools—ps, dstat, top, and htop—by mapping each command to a character from the classic “Four Great Detectives,” while covering essential options, output fields, and practical tips for effective system observation.
This guide provides a concise reference of essential Linux commands for file handling, process control, networking, system information, and package management, helping users quickly perform common administrative tasks from the command line.
This guide explains how to use the Linux /usr/bin/time utility to analyze program performance—including user and kernel CPU time, memory usage, and other resources—by invoking the command with various options, customizing output formats, redirecting results, and distinguishing it from the shell built‑in time command.
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.
