Retrieving hardware serial numbers is essential for inventory management, warranty tracking, and identifying physical servers across your infrastructure. The standard approach uses dmidecode, which reads the system’s DMI (Desktop Management Interface) data. Using dmidecode First, install the tool: sudo apt-get install dmidecode For Rocky Linux, RHEL, and derivatives: sudo dnf install dmidecode Then query the…
I/O schedulers in Linux sit between application requests and physical disk hardware, deciding the order in which I/O operations execute. The fundamental difference between work-conserving and non-work-conserving schedulers comes down to how they handle idle periods. Work-Conserving Schedulers A work-conserving scheduler must dispatch a pending I/O request whenever one exists, regardless of physical disk positioning….
Interrupts are fundamental to how your Linux system handles hardware and software events. Monitoring them in real-time helps identify performance bottlenecks, device driver issues, and CPU load imbalances. Here’s how to check interrupts effectively. Quick Live Monitoring with /proc/interrupts The simplest approach is reading /proc/interrupts directly: cat /proc/interrupts This shows a snapshot of interrupt counts…
Achieving high performance in virtualized environments requires careful tuning of kernel parameters, CPU idle states, and hypervisor settings. The goal is to reduce context switching overhead, minimize latency, and keep vCPUs busy rather than cycling through low-power states. Kernel Boot Parameters Add these parameters to your kernel boot line in /etc/default/grub: intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll intel_pstate=disable…
When you need to break up a large gzip file into smaller chunks, you have several practical options depending on your constraints. Using zcat with split The most straightforward approach is to decompress the gzip file and split it simultaneously: zcat large_file.gz | split -b 100M – chunk_ gzip chunk_* This decompresses large_file.gz, pipes it…
C++ remains a foundational language for systems programming and performance-critical applications. Here’s what actually matters when choosing C++ for a project. Zero-Cost Abstraction This is C++’s defining characteristic. You get high-level language features—classes, templates, standard library containers—without paying runtime overhead. The compiler eliminates abstraction layers during compilation. This means you can write clean, maintainable code…
Processing files line by line is a common task in systems programming, data processing, and log analysis. C++ provides several approaches with different trade-offs in performance, memory usage, and code clarity. Using std::getline with std::ifstream The most straightforward approach uses std::getline with an input file stream: #include <fstream> #include <string> #include <iostream> int main() {…
These are often confused terms in concurrent programming and multiprocessor systems, but they address different problems in shared memory architectures. Memory Coherence deals with writes to the same memory location. A cache-coherent system ensures that any read of a data location returns the most recently written value. If CPU A writes to address X, then…
[md] The RTL8192cu is a legacy USB WiFi adapter that’s still in use, but it has known stability issues on modern kernels. If your adapter keeps dropping connections or fails to resume after sleep, you’re likely hitting the same power management bug that affects many devices. ## Disable Power Management The most reliable workaround is…
The kernel log buffer (dmesg) outputs timestamps in seconds since boot by default, making it difficult to correlate events with wall-clock time or other system logs. Here’s how to convert them to human-readable format. Using journalctl Instead of dmesg The modern approach is to use journalctl, which handles timestamp formatting automatically: journalctl -b This shows…
Tethering your iPhone to your computer’s internet connection via USB is useful when you need a stable, low-power connection or want to avoid wireless overhead. This guide covers the practical setup on Windows and how to configure your iPhone to use your PC’s internet. Windows USB Tethering Setup On Windows 10/11: Install iTunes or Apple…
MATE Desktop provides a traditional GNOME 2-style interface that many users prefer over modern GNOME Shell. Here’s how to install it on Linux Mint 17 Qiana. Install MATE Desktop sudo apt-get update sudo apt-get install mate-desktop-environment For the full MATE experience with extras: sudo apt-get install mate-desktop-environment-extras This adds additional applets, themes, and utilities not…
mpv is a powerful media player for Linux that supports looping videos with minimal configuration. Here’s how to loop videos in fullscreen mode using mpv. Loop a Single Video The simplest way — use the –loop flag: mpv –fullscreen –loop video.mp4 –loop replays the video infinitely. To loop a specific number of times: # Loop…
Monitoring directory growth is essential for tracking logs, temporary files, and catching runaway disk usage before it becomes a problem. Linux offers several approaches depending on whether you need simple periodic checks, interactive exploration, or event-driven monitoring. Simple periodic monitoring The watch command repeatedly runs a command at set intervals: watch -n 1 du -sh…
While BIOS settings are the preferred way to disable USB 3.0, you can also force USB 2.0 mode on a running Linux system by manipulating the xHCI controller’s port routing register directly using setpci. How it works Intel xHCI controllers use the XUSB2PR (xHC USB 2.0 Port Routing Register) at offset 0xd0. Setting this register…
SSD performance varies significantly based on drive model, interface (NVMe vs SATA), and workload characteristics. Understanding how to benchmark your drives is more useful than memorizing typical specs—here’s how to measure actual throughput on your hardware. Basic Throughput Testing with dd The dd utility is the simplest way to measure sequential I/O performance. Here’s a…
The default display manager on Fedora is GNOME Display Manager (GDM). If you want to switch to another display manager like KDE Plasma (SDDM), LightDM, or another option, you need a reliable method that won’t break your system. Using system-switch-displaymanager The most straightforward approach is the system-switch-displaymanager utility, which handles the systemd configuration for you….
When you try to create a filesystem on a disk with mkfs, you may see this error: # mkfs -t ext4 /dev/sdd1 mke2fs 1.42.8 (20-Jun-2013) /dev/sdd1 is apparently in use by the system; will not make a filesystem here! Even though the device isn’t mounted, mkfs refuses to proceed. This safety mechanism prevents accidental data…
These kernel messages from the libata driver indicate SATA link-layer errors between your drive and controller. They look alarming, but they’re usually fixable — and the fix is typically hardware-related, not a software or drive firmware issue. What These Error Messages Mean When you see messages like this in dmesg: ata4.00: exception Emask 0x10 SAct…
Lightning cables are everywhere, but not all of them work reliably with iPhones. If you’ve bought a cheap third-party cable that stopped working or wouldn’t charge properly, you’ve hit the core problem: counterfeit and non-certified cables are rampant online and in retail stores. The safest approach is buying directly from Apple, but that’s not always…