Xen remains a solid hypervisor choice for specific workloads, though KVM dominates most Linux distributions today. This guide covers installing a paravirtualized DomU on Xen using modern tooling and Rocky Linux 9, which requires specific kernel parameters during installation. Why Paravirtualization Matters Paravirtualized guests communicate directly with the hypervisor rather than emulating hardware, resulting in…
USB technology continues evolving with each generation delivering significant speed improvements. Linux provides comprehensive kernel support across all modern standards through dedicated drivers. USB 2.0 Speed: 480 Mbps (theoretical ~60 MB/s) Status: Legacy but still common. Nearly all systems retain USB 2.0 ports for backward compatibility. Linux support: Built-in via the ehci-hcd driver in all…
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…
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….
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…
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…
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…
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…
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…
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…
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….
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…
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…
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….
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:…
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…
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…
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…
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…
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…