This article examines how changing the InnoDB parameters innodb_flush_method and innodb_use_fdatasync—especially using O_DIRECT—affects MySQL's interaction with Linux syscalls, demonstrates verification with strace and /proc, and shows performance implications of these low‑level I/O choices.
This article systematically explains epoll’s internal data structures, how the protocol stack notifies it, the locking strategy for thread safety, the differences between edge‑triggered and level‑triggered modes, and why it outperforms select/poll in high‑concurrency Linux I/O.
DPDK enables low‑cost commodity servers to achieve high‑throughput, low‑latency packet processing by bypassing the kernel, offering flexible processing models, supporting user‑space networking stacks, and being adopted across telecom, cloud, and edge environments despite challenges such as debugging and CPU usage.
A single server‑side process can theoretically handle up to 2^48 (≈2.8×10^14) TCP connections, but Linux file‑descriptor limits and memory consumption (about 3.44 KB per connection) restrict real‑world capacity to a few million connections per 8 GB machine, while a whole server’s total is bounded by the same resource constraints despite the much larger theoretical maximum.
This guide provides complete shell scripts and step‑by‑step instructions for performing remote backups and restores of MySQL, Oracle, and PostgreSQL databases on Linux, including directory creation, compression, secure copy, cron scheduling, and cleanup of old backup files.
This tutorial walks you through Linux process creation with fork, explains copy‑on‑write mechanics, details process termination, waiting, and program replacement using exec families, and culminates in building a basic shell, complete with code examples and visual illustrations.
This guide walks you through installing and using the rzsz utility to transfer files between Windows and remote Linux machines via XShell, covering network checks, package installation, and both drag‑and‑drop and command‑line methods for uploading and downloading.
This guide explains how to read, set, and permanently configure Linux environment variables—especially PATH—using six different methods, and reveals the exact order in which the system loads these variable files.
Explore ten entertaining Linux commands—including rev, asciiview, sl, aafire, cmatrix, factor, oneko, boxes, xeyes, and pv—detailing their installation, usage examples, and visual effects that transform your terminal into a playful, educational environment.
The article investigates why BPF LSM programs fail to load on aarch64 kernels, uses ftrace‑based tools such as bpftrace and trace‑cmd to trace kernel execution, discovers missing arch_prepare_bpf_trampoline support in 5.15 and 6.1, and shows that a patch merged into the mainline kernel restores functionality for upcoming releases.
This guide walks you through setting up a Palworld private server on a cloud VM by preparing an Ubuntu/Debian machine, installing SteamCMD, creating a dedicated user, downloading and configuring PalServer, opening port 8211, and launching it with nohup, plus troubleshooting tips.
This guide explains how to manage Linux user groups—including creating, renaming, changing GIDs, deleting groups, adding or removing users, viewing group details, switching groups, setting group passwords, and adjusting file ownership—through clear command‑line examples and practical scenarios.
This guide explains how to use the Linux file command to identify single or multiple files, recognize text, binary, compressed, and image types, apply recursive and MIME‑output options, combine it with other utilities, and embed it in shell scripts for automation.
This guide provides practical Linux‑based MySQL administration scripts covering connection, backup and restore, table optimization, log cleanup, performance monitoring, automated cron jobs, security best practices, replication management, and user permission handling.
This guide explains how to use the stress and dd utilities together with a custom shell script to artificially consume CPU, memory, and disk resources on idle cloud servers, helping avoid budget cuts by keeping resource utilization high for a configurable period.
This article provides a thorough walkthrough of the nmcli command-line tool on Linux, covering installation, basic usage, managing Ethernet, Wi‑Fi, and VPN connections, advanced batch configurations, scripting automation, and useful aliases, complete with practical code examples for each scenario.
This article reviews the key features, advantages, and command‑line examples of major Linux file systems—including ext4, Btrfs, XFS, ZFS, F2FS, and OverlayFS—to help you select the most suitable one for performance, reliability, and specific workload requirements.
This guide explains how to install and use the Linux watch command for periodic command execution, system‑load monitoring, live log viewing, custom script scheduling, and several advanced options such as custom intervals, output redirection, screen clearing, timestamps, and display formatting.
This article walks through the three-stage Linux boot sequence—power‑on, BIOS/UEFI initialization, and kernel startup—detailing the role of MBR, GRUB2, init processes, runlevels, fstab configuration, and user login mechanisms.
This guide walks through four practical methods to create a local YUM repository on CentOS—using a Bash script, mounting an ISO image, configuring the official Aliyun mirror, and sharing via an HTTP server—complete with commands, configuration files, and troubleshooting tips.
This guide walks through six ways to configure Linux environment variables—including export commands, editing ~/.bashrc, ~/.bash_profile, /etc/bashrc, /etc/profile, and /etc/environment—while also detailing how the system loads these files and offering practical tips for testing and customizing variable definitions.
This guide explains how to secure Linux servers by configuring sshd to allow or deny specific users or IPs, using hosts.allow/hosts.deny for IP filtering, and setting up iptables rules to open only required ports while blocking all others.
Learn why SSH connections drop due to TCP timeout settings and follow step‑by‑step Linux, Windows (PuTTY), and server‑side configurations—including tcp_keepalive and ServerAlive options—to keep remote sessions active and avoid idle‑disconnects for developers.
This article compiles 50 high‑frequency interview questions covering Linux embedded systems, including CAN bus, bare‑metal programming, real‑time scheduling, interrupt handling, kernel modules, memory management, and various Linux kernel mechanisms, providing concise explanations and code examples for each topic.
This tutorial explains how to prepare nodes, install required packages, configure cephadm, bootstrap a Ceph cluster, add monitors, managers, OSDs, and verify the deployment using command‑line operations on Rocky Linux systems.
This guide introduces three essential Linux I/O tools—iostat for disk activity and CPU stats, iotop for real‑time per‑process I/O usage, and lsof for listing open files—detailing installation, key output fields, common options, and practical usage examples.
This guide introduces the free, secure, and continuously updated 1Panel visual management panel for Linux servers, explains its key features, shows one‑line installation commands for CentOS and Ubuntu, and details access, security, backup, and upgrade procedures.
This guide compiles essential Linux keyboard shortcuts for the terminal, desktop navigation, Orca screen reader, Firefox, Gedit, and Nautilus, helping users work faster by mastering key combinations for navigation, editing, window management, and application control.
This guide explains the versatile Linux ‘!’ history‑expansion operator, showing how to repeat previous commands, substitute arguments, use wildcards, edit past entries, and apply safety tips, all with clear examples to boost command‑line efficiency.
Docker leverages Linux cgroups to limit and schedule CPU usage for containers, allowing users to set a maximum number of CPU cores with the --cpus flag while keeping the actual cores dynamically allocated, ensuring other host processes can still access unassigned CPUs.
This guide provides a comprehensive overview of Linux operating system fundamentals, covering file system structure, essential command-line tools, user and group management, permission handling, process control, and common software installation methods.
This guide walks you through checking CPU usage, system load, process resources, tracing problematic processes, reviewing system logs, and using performance tools like perf to pinpoint and resolve Linux server bottlenecks.
This tutorial walks through installing TigerVNC on a Rocky Linux 8.9 server, creating VNC users, configuring systemd services, opening firewall ports, and connecting from a Windows 10 client with UltraVNC Viewer, providing all necessary commands and screenshots for a fully functional remote desktop setup.
This guide shows how to compile a C program, use GDB to pretty‑print complex structures, enable indexed array printing, suppress startup banners, and automate these settings with a .gdbinit script for a clearer, more efficient debugging experience.
This article explains the Linux kernel ftrace architecture, covering ring buffer principles and code, tracer implementations (function, function_graph, irq_off), trace events, dynamic and static instrumentation, and kprobe mechanisms, illustrating how tracing is integrated, managed, and optimized for various execution contexts.
Learn how to dramatically speed up your Linux command line workflow by mastering essential Bash navigation, editing, history, and process‑control keyboard shortcuts, each illustrated with clear examples and images, so you can work more efficiently and confidently in the terminal.
This comprehensive guide compiles 35 essential Linux operations interview questions covering server management, RAID configurations, load balancing with LVS/Nginx/HAProxy, proxy choices, middleware, MySQL troubleshooting, networking tools, security practices, and practical scripts, providing concise answers to help candidates ace DevOps and sysadmin roles.
A comprehensive collection of over 100 Linux system and kernel interview questions, covering topics such as distributions, package management, process monitoring, memory management, file systems, system calls, concurrency, C/C++ language features, data structures, algorithms, and practical code examples for developers preparing for technical interviews.
This guide walks through installing and configuring the open‑source Nightingale monitoring platform on a Linux server, including prerequisite MySQL and Redis setup, Prometheus deployment, Nightingale binary installation, service configuration, and adding the Categraf collector for comprehensive system metrics.
This guide explains how to use Linux command-line utilities like journalctl and dmesg, directly inspect common log files such as /var/log/messages and /var/log/syslog, and employ graphical log viewers including GNOME Logs, KSystemLog, and Logwatch for effective system monitoring and troubleshooting.
Three real-world operations mishaps are recounted—a mistaken system‑time change that logged out thousands of users, an accidental bulk delete of database accounts, and a failed glibc downgrade that stalled a software release—illustrating the cascading impact of small errors and the urgent remediation steps taken.
This guide explains four ways to create a local YUM repository on CentOS 7—using a Bash script, mounting an ISO image, configuring the official Aliyun mirror, and sharing the repository over a LAN with httpd—complete with commands, configuration files, and troubleshooting tips.
This article explains the Linux kernel boot sequence on ARM platforms, covering how the compressed kernel is decompressed, the role of the stext entry point, the preparation steps performed by __switch_data, and the detailed initialization performed by start_kernel and its key sub‑functions.
Learn how to view and analyze Linux system logs using command-line utilities like journalctl and dmesg, explore key log files such as /var/log/messages and /var/log/auth.log, and discover graphical tools like GNOME Logs and Logwatch for effective troubleshooting and performance monitoring.
This comprehensive guide lists essential Linux commands for system information, shutdown, file management, searching, mounting, disk usage, user and group handling, permissions, special attributes, packaging, RPM/YUM/DEB management, network utilities, and Vim editing, providing clear examples and options for each task.
The Linux top command offers a dynamic, real‑time view of system processes and resource usage—showing overall statistics, CPU and memory breakdowns, and detailed process columns—while supporting customizable refresh intervals, batch mode, and interactive shortcuts for sorting, column selection, and monitoring crucial metrics like %idle, %wa, and %steal.
This guide walks through installing, configuring, and verifying Chrony on two Rocky Linux 8.9 servers, showing how to sync with public NTP sources and between servers, including firewall settings and detailed output interpretation.
This guide explains how to use the Linux top command to monitor real‑time process changes, interpret system and process statistics, apply command‑line options, perform common interactive operations, and understand CPU steal time for virtualized environments.
This tutorial walks through installing NFS utilities, configuring the server and client, setting export permissions, enabling required services and firewall rules, and mounting the shared directory permanently on Rocky Linux 8.9 systems.
This guide walks you through checking CPU usage, system load, resource consumption, process tracing, log inspection, and performance bottleneck analysis on Linux to pinpoint and resolve high CPU utilization issues.
This article explains the Linux kernel boot sequence, covering the decompression of a compressed kernel, the early startup code in head.S, the preparation steps performed by U-Boot, and the detailed initialization phases—including architecture setup, memory management, process creation, and the start_kernel routine.
This article introduces Redis, explains its key advantages as an in‑memory data store, provides step‑by‑step installation instructions for CentOS including required packages, and demonstrates basic commands to start the server and interact with the database.
This article explains Direct Memory Access (DMA), compares it with traditional I/O, details the complete DMA‑based I/O workflow, and explores zero‑copy techniques such as mmap, sendfile, and asynchronous I/O, highlighting their impact on context switches, data copies, and overall transfer performance.
This guide walks you through preparing Linux machines, configuring system settings, installing Docker and Kubernetes components with kubeadm, initializing a master node, deploying a pod network, joining worker nodes, and verifying the cluster, providing a complete step‑by‑step tutorial for building a Kubernetes cluster.
This article provides a comprehensive guide to five methods for running Python scripts in the background on Linux, covering nohup with &, screen sessions, systemd services, Celery task queues, and supervisord, including command examples and configuration steps.
This guide explains how to install Webman, configure the project, build a self‑contained binary for x86_64 Linux using PHP's phar mechanism, run and monitor the binary, and outlines important compatibility notes and alternative manual packaging methods.
This tutorial explains how the chmod options u+x and +x differ in assigning execute permissions, details the symbolic mode syntax, shows how the umask setting can change their behavior, and provides practical command examples for Linux file permission management.
This guide explains how to use the Linux type command to identify whether a command is built‑in, external, or an alias, display its location, retrieve its full path, and list all possible occurrences, with clear examples for each option.
This guide explains how to use Linux’s mount command to attach local disks, network shares, and ISO images, covering basic syntax, common options like -t and -o, automatic mounting via /etc/fstab, and important security considerations.
This article provides a comprehensive, hands‑on tutorial for Linux Logical Volume Manager (LVM), covering installation environment setup, creating physical volumes, volume groups, logical volumes, extending them, resizing file systems, and adding new disks, complete with command‑line examples and explanations.
This guide introduces Chrony, an open‑source NTP client for Unix‑like systems, and walks through setting up a two‑server lab on Rocky Linux, configuring chronyd and chronyc, adjusting firewall rules, and interpreting synchronization status to achieve precise time keeping.
The article reports on Google’s planned 30,000‑plus layoffs amid its AI transformation, OpenAI’s annual revenue surpassing $1.6 billion, the EU’s upcoming JUPITER exaflop supercomputer built with 24,000 Nvidia GH200 GPUs, and a Linux developer’s claim that a 22° screen rotation offers the optimal view for software development.
This article provides a thorough walkthrough of tcpdump, covering installation on Ubuntu, essential command‑line options, practical filtering techniques, logical expressions, examples for saving and reading capture files, and how to combine tcpdump with Wireshark for deeper packet analysis.
This article explains the Linux Netlink mechanism, its protocol families, advantages over ioctl and /proc, detailed user‑space socket usage, and the kernel‑side APIs required to create, send, receive, and manage Netlink messages, including code examples.
This article provides a comprehensive, step‑by‑step tutorial on setting up a server, configuring VMware, establishing remote connections, uploading front‑end assets, and configuring Nginx to deploy a front‑end project from scratch, targeting beginners who lack deployment experience.
This guide explains why manual log review is tedious, introduces Logwatch as an automated solution, walks through installing it on CentOS, configuring its core settings, running it manually, and interpreting its concise email reports to simplify Linux system log management.
This guide introduces the PHP Event extension, outlines its libevent and OpenSSL dependencies, and provides detailed step‑by‑step commands to install libevent, compile and configure the PHP Event extension, modify php.ini, and verify the installation on a Linux server.
Linus Torvalds announced a holiday break during Christmas, postponing the final Linux 6.7 release to early January and explaining the impact of the season on the kernel release schedule and upcoming release candidates.
This guide explains what NFS is, walks through setting up a Rocky Linux NFS server and client, covers installing packages, configuring export directories, adjusting permissions, editing /etc/exports, enabling rpcbind and NFS services, opening firewall ports, and mounting the share on the client.
This guide walks you through downloading, compiling, and installing PHP 8.3 from source, configuring PHP‑FPM, creating systemd service files, and then installing ThinkPHP 8.0 with Composer, including Nginx setup and verification steps to get a working PHP web application.
This article explains a three‑step method—using top to locate the CPU‑hungry Java process, identifying the offending thread, and printing its stack with jstack—to pinpoint and resolve excessive CPU consumption in a Java application running on Linux.
This article explains how the Linux kernel allocates dynamic memory, distinguishes kernel and user‑space allocation strategies, describes the mm_struct layout of a process address space, and shows how pages and page tables translate virtual addresses to physical memory.
dperf, Baidu’s open‑source DPDK‑based tool, delivers ultra‑high‑performance network testing by generating up to ten million HTTP connections per second, hundreds of gigabits of throughput, and detailed per‑second statistics, with step‑by‑step guidance on environment setup, compilation, and execution.
This guide explains how to install lm_sensors, write a Bash script to retrieve CPU temperature, configure a Zabbix agent UserParameter, restart the agent, and set up a corresponding monitoring item on the Zabbix server, enabling automated CPU temperature monitoring.
Real‑time monitoring of CPU, memory, disk I/O and network bandwidth during performance testing helps identify bottlenecks, prevent crashes, collect actionable data, ensure accurate results, and meet SLA requirements, and a Python script can automate data collection and storage in MySQL.
This article explains how to create a basic web crawler in a Linux environment using PHP, covering prerequisite installations, script development with cURL and DOMDocument, execution steps, and sample output while emphasizing legal and ethical considerations for web scraping.
This tutorial walks you through Hadoop’s core components, sets up a single‑node Hadoop cluster on CentOS 7, installs Python 3, writes mapper and reducer scripts in Python, and runs a Hadoop‑Streaming word‑count job to demonstrate classic big‑data processing techniques.
Learn how to view and interpret IP addresses on Windows and Linux using commands like ipconfig, ifconfig, and ip addr, understand the differences between ifconfig and ip addr, explore IPv4 classes, CIDR notation, public vs private IPs, and MAC addresses, and network interface flags.
This article presents a comprehensive collection of CVTE embedded engineering interview questions and answers, covering project introductions, C/C++ operators, the static keyword, pointers vs. references, copy constructors, Linux sed usage, file system types, I²C limits, interrupt handling, recursion, IPC, GPIO modes, and compilation stages, providing clear explanations and code examples for each topic.
This article explains three common Linux startup methods—traditional /etc/rc.local, legacy SysVinit scripts in /etc/init.d/, and the modern systemd unit system—detailing their roles, execution contexts, and how systemd has largely replaced older approaches.
This article details a step‑by‑step analysis of a server experiencing sustained high load, uncovering a stuck NFS mount and an overactive Zabbix monitoring job, and explains how targeted process termination and monitoring adjustments reduced the load from 85 to normal levels.
This article examines memory usage on a Junzheng T31ZC embedded Linux board, breaks down physical and kernel allocations, and presents practical techniques—such as trimming kernel symbols, stripping ELF files, optimizing rootfs, and manually dropping caches—to reclaim valuable RAM without adding hardware.
This article provides a comprehensive interview guide for embedded system positions, covering Linux thread scheduling, single‑core CPU execution, STM32 chip specifications, SPI communication, DMA, synchronization primitives, priority inversion solutions, debugging techniques, and memory layout fundamentals.
This guide shows how to modify non‑standard configuration files such as wpa_supplicant.conf by using the sed command‑line tool and wrapping the commands in a C program to automate Wi‑Fi SSID and password updates.
This article explains the Linux page‑reclaim mechanism, its goals, common techniques, the allocation paths, LRU data structures, and provides an in‑depth walkthrough of the kernel source code for slow‑path reclaim, direct reclaim, and memory compaction, including all relevant functions and code snippets.
At a recent open‑source summit in Japan, Linus Torvalds discussed the upcoming Linux 6.7 release, the growing role of Rust in the kernel, maintainer fatigue, and how artificial intelligence may assist developers while highlighting the social challenges of open‑source collaboration.
This article explains how Linux processes can share large data efficiently by creating a memory file with memfd_create, mapping it with mmap, and transferring the file descriptor over a Unix Domain Socket, while detailing the kernel mechanisms that enable true cross‑process memory sharing.
This article explains the principles and usage of dynamic memory allocation in C/C++ (malloc, calloc, realloc, free, new, delete), compares their behaviors, demonstrates common pitfalls, and extends the discussion to Linux kernel memory statistics, cache handling, swappiness tuning, and garbage‑collection concepts.
This article compiles insights from multiple Zhihu contributors who explain how modern operations work spans basic system setup, complex hardware and network management, deep Linux kernel debugging, comprehensive monitoring, rapid incident response, and rigorous security, highlighting why ops expertise is essential and far from low‑level.
This article provides an in‑depth overview of Linux memory management, covering the three primary allocators—bootmem, buddy, and slab—including their data structures, initialization, allocation and free mechanisms, code examples, and the role of memblock and zone watermarks.
This comprehensive guide explains the core Linux text‑processing utilities—awk, grep, and sed—covering their purposes, syntax, common options, powerful regular‑expression features, practical examples, control structures, arrays, functions, and how they compare to each other for efficient command‑line data manipulation.
Discover four powerful Linux terminal utilities—TheFuck for auto-correcting mistyped commands, btop for interactive system monitoring, fzf for fast fuzzy file searching, and tldr for concise command cheat sheets—along with installation steps, usage examples, and customization tips to streamline your workflow.
This guide walks you through understanding what a Raspberry Pi is, the specifications of the Zero W model, preparing the SD card, flashing Raspbian, configuring SSH and Wi‑Fi, optimizing the system, installing Nginx, and exposing the device to the Internet with ngrok.
This article explains Ceph RBD QoS concepts, describes a full testing environment and workflow, shows command‑line configurations and fio benchmarks, and summarizes the findings that image‑level QoS limits are effective while pool‑level limits are not.
This guide walks you through obtaining a valid SSL certificate, installing Nginx on a Linux server, configuring the HTTPS server block, converting certificates to PEM format, and testing the secure connection, providing step‑by‑step commands and example configurations.
D‑Eyes is an open‑source detection and response tool from NSFOCUS that runs on Windows and Linux, offering command‑line utilities to scan files, processes, host information, network connections, and perform baseline and software‑supply‑chain checks, with built‑in YARA rules for ransomware, mining malware, botnets, and webshells.
This article explains the fundamentals of memory‑mapped files in Linux, covering the mmap/munmap interfaces, mapping types, protection flags, error handling, virtual‑memory structures, kernel implementation details, driver examples, and practical use‑cases such as shared memory and high‑performance I/O.
This article shares a comprehensive embedded software interview guide, covering written‑test topics such as structs vs. unions, linked lists, pointer safety, endianness detection, and a strcpy implementation, followed by technical interview tips, HR interview advice, and concluding remarks.
This guide presents a collection of practical Linux shell commands and scripts for locating and moving files, batch extracting archives, using sed for text manipulation, checking directories, monitoring disk usage, analyzing logs, and configuring firewalls, all illustrated with clear examples and explanations.
The Java service crashed when the Linux OOM killer terminated its process after a developer opened a 37 GB log file with Vim, which loaded the entire file into the container’s 8 GB memory, triggering a port alarm and prompting investigation and recommendations to use streaming tools instead of Vim.
