SysTutorials Posts

Linux & Systems Administration

Building and Installing a Linux Kernel from Source
ByEric Ma Mar 18, 2017Apr 12, 2026

Grab a release from kernel.org. Recent stable versions (6.x and later) are recommended for production systems: wget https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz tar xf linux-6.12.tar.gz cd linux-6.12/ If wget isn’t available, use curl: curl -O https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz Verify the tarball Always verify the kernel’s integrity using checksums and signatures published on kernel.org. This is essential for production systems: wget https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz.asc…

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Linux System Configuration

Linux System Monitoring with Data Visualization
ByJoseph Macwan Feb 24, 2017Apr 12, 2026

Data visualization transforms raw metrics into actionable insights. When you’re managing infrastructure metrics, application logs, business KPIs, or system performance data, visualization is how you extract signal from noise. The human brain processes visual information faster and more reliably than log files or spreadsheet rows—which is why dashboards have become essential infrastructure in modern operations….

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Linux & Systems Administration

Linux Kernel’s taskstats: Per-Task Performance Metrics
ByWeiwei Jia Feb 14, 2017Apr 12, 2026

The Linux kernel provides the taskstats API to monitor detailed per-task statistics, including I/O wait time, CPU scheduling delays, and memory reclamation waits. Understanding how these metrics are collected at the kernel level is essential for diagnosing performance issues and understanding process behavior. How the Kernel Records I/O Delays The kernel records I/O wait delays…

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Languages & Frameworks

Getting Started: How to Choose Your First Programming Language
ByJoseph Macwan Feb 6, 2017Apr 12, 2026

Picking your first programming language matters, but it’s not the career-defining decision some make it out to be. What matters more is that you pick something reasonable and start building. That said, some choices will save you months of frustration. Know What You’re Optimizing For Before evaluating languages, answer these questions honestly: What do you…

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Linux & Systems Administration

Mastering Vim: A Practical Guide to vimtutor
ByEric Ma Dec 31, 2016Apr 12, 2026

vimtutor is the most practical way to learn Vim. It’s an interactive lesson built directly into your editor that teaches through practice rather than passive reading. You launch it from the terminal with no setup required, and you get immediate feedback on every command you type. Running vimtutor From any terminal: vimtutor This opens an…

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Languages & Frameworks

Building Java CLI Applications with Spring Shell 3.x
ByJohnnymorgan Dec 23, 2016Apr 12, 2026

Spring Shell is a framework for building command-line interfaces (CLIs) in Java applications. It provides structured command definition, argument parsing, tab completion, and history management—all integrated with the Spring ecosystem. Requirements and Setup Spring Shell 3.2+ requires Java 17+ and Spring Boot 3.2+. If you’re still on older versions, Spring Shell 2.x supports Java 8…

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Linux & Systems Administration

Reducing QEMU/KVM Lock Contention with IOThreads and Dataplane
ByWeiwei Jia Dec 18, 2016Apr 12, 2026

QEMU/KVM uses global locks to synchronize threads, which is necessary for correctness but causes performance problems at scale. When multiple I/O requests and vCPU threads contend for the same lock, you get lock contention that manifests as scheduling jitter, reduced system scalability, and degraded I/O performance. IOThreads (the modern implementation of dataplane) address this by…

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Algorithms & Data Structures

Conditional Dropdown Filtering in Dynamics 365: Filter Salutation by Gender
ByEthan Millar Dec 15, 2016Apr 12, 2026

Filtering dependent fields based on parent field values is a common requirement in Dynamics 365 CRM. This guide walks through implementing conditional filtering so the salutation dropdown only shows values relevant to the selected gender. Prerequisites Access to a Dynamics 365 environment (2016 or later) with customization rights Basic understanding of option sets and form…

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Algorithms & Data Structures

Filter Dependent Lookup Fields in Dynamics 365 and Power Apps
Byjameswarner Dec 9, 2016Apr 12, 2026

Filtering a dependent lookup field based on another lookup field’s value is a core requirement in Dynamics 365 and Power Apps. The classic example: a Lead entity with Branch and Sub Branch fields where Sub Branch options should only display records matching the selected Branch. The form editor handles this natively—no plugins or JavaScript required….

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Linux & Systems Administration

Measuring CFS Scheduler Timeslices in Linux
ByWeiwei Jia Dec 5, 2016Apr 12, 2026

CFS (Completely Fair Scheduling) is the default process scheduler in modern Linux kernels. Understanding actual timeslice allocation—how long a process runs before being context-switched out—is essential for performance debugging, verifying fairness assumptions, and identifying scheduling anomalies. The challenge is that /proc interfaces and ps commands show scheduling policy but not the actual on-CPU duration per…

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Algorithms & Data Structures

Converting Managed Solutions to Unmanaged in Dynamics CRM
Byjameswarner Dec 3, 2016Apr 12, 2026

Converting a managed solution to unmanaged in on-premise Dynamics CRM requires direct database modification. You’ll need this when customizing third-party solutions that the publisher hasn’t provided in unmanaged form, or when you need to export and modify components before deployment. Prerequisites Full database backup (this modifies system tables — non-negotiable) SQL Server Management Studio or…

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Linux & Systems Administration

How the CFS Scheduler Controls Process Timeslices and Preemption
ByWeiwei Jia Dec 1, 2016Apr 12, 2026

The Completely Fair Scheduler (CFS) is the default process scheduler in Linux kernels since 2.6.23. It allocates CPU time proportionally based on process priority, but the actual timeslices and preemption behavior depend on three key tunable parameters: sched_latency_ns, sched_min_granularity_ns, and sched_wakeup_granularity_ns. Understanding how these work together is essential for tuning scheduler behavior on production systems….

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Languages & Frameworks

Building a REST API with ASP.NET MVC and JavaScript
Byjameswarner Nov 25, 2016Apr 12, 2026

This guide covers building REST endpoints in ASP.NET MVC and consuming them from a frontend application. While this example uses AngularJS (end-of-life 2022), the backend patterns remain relevant for legacy system maintenance. For new projects, migrate to ASP.NET Core with modern frontend frameworks like React, Vue, or Angular. Database Setup Create the parts inventory table:…

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Linux & Systems Administration

How Linux Kernel Migration Threads Work
ByWeiwei Jia Nov 19, 2016Apr 12, 2026

In computer systems, resources must be balanced across available hardware to maximize performance. The Linux kernel runs migration threads as per-CPU daemons to handle this work. These threads manage task migration between CPUs, CPU hotplug operations, and stop-machine synchronization. You can observe migration threads on any modern system: $ ps aux | grep migration root…

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Linux & Systems Administration

How sched_setaffinity Works in the Linux Kernel
ByWeiwei Jia Nov 9, 2016Apr 12, 2026

CPU affinity binds a process or thread to specific CPU cores, reducing cache misses, improving performance isolation, and managing NUMA locality. The sched_setaffinity() system call is the primary mechanism in Linux. Understanding how it works at the kernel level clarifies scheduler internals and helps you use it effectively. System Call Entry Point The sched_setaffinity() syscall…

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Scripting & Utilities

GNOME Shell Extensions to Enhance GNOME 45
ByEric Ma Oct 22, 2016Apr 12, 2026

GNOME Shell’s clean, minimal design works well for many users, but the extension ecosystem lets you adapt it to your actual workflow. Here are extensions worth considering for modern GNOME (45+). AlternateTab Changes Alt-Tab behavior from application-grouped switching to per-window switching — more like traditional window managers. If GNOME’s default grouping feels disruptive, this restores…

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Linux & Systems Administration

Building 32-bit Wine on CentOS 7, Rocky Linux, and AlmaLinux
ByEric Ma Oct 16, 2016Apr 12, 2026

RHEL-based distributions only provide 64-bit Wine packages in their standard repositories. Many Windows applications—especially legacy software—require 32-bit Wine. Building Wine from source is the most reliable approach to get a working 32-bit installation alongside 64-bit support. Prerequisites and Resource Requirements Building Wine requires significant resources: ~2GB temporary disk space, ~500MB installed Compilation takes 20-40 minutes…

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Linux System Configuration

Managing Third-Party Repositories on CentOS, Rocky Linux, and AlmaLinux
ByEric Ma Oct 15, 2016Apr 12, 2026

Modern RHEL-based systems (EL9+) ship with dnf as the package manager. Most additional software you’ll need comes from well-maintained third-party repositories rather than compiling from source. This guide covers the essential ones and how to use them safely. EPEL (Extra Packages for Enterprise Linux) EPEL is the go-to third-party repository for RHEL-based systems. It provides…

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Linux & Systems Administration

Switching Linux Systemd Boot Targets
ByEric Ma Sep 17, 2016Apr 12, 2026

Systemd replaced traditional init on most modern Linux distributions, shifting terminology from “runlevels” to “targets.” If you’re migrating from older systems, here’s the mapping: Runlevel Systemd Target Purpose 0 poweroff.target Shutdown 1 rescue.target Single-user mode 2, 3, 4 multi-user.target Multi-user, no GUI 5 graphical.target Multi-user with GUI 6 reboot.target Reboot The two targets you’ll use…

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Languages & Frameworks

Client-Side Routing in AngularJS: Managing Route Parameters
Byjameswarner Aug 19, 2016Apr 12, 2026

AngularJS routing enables single-page applications by dynamically switching views based on URL patterns without full page reloads. Unlike server-side routing, AngularJS handles routing on the client, eliminating network round-trips and improving responsiveness—particularly useful when displaying different datasets based on route parameters. Install AngularJS and Dependencies Include AngularJS and the routing module. Using npm: npm install…

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