When managing LVM storage, you need to know which physical disks support each logical volume — especially for risk assessment when hardware fails. This guide shows you how to trace those relationships. Using lvdisplay to map extents The lvdisplay command with the –maps flag shows how logical extents map to physical volumes: lvdisplay –maps This…
The x86-64 ISA provides ucomiss and ucomisd for comparing SSE floating-point values. These instructions compute S1 – S2 and set the EFLAGS register (ZF, PF, CF) based on the result. Instruction Operands Purpose ucomiss S2, S1 Compare single-precision (32-bit) floats ucomisd S2, S1 Compare double-precision (64-bit) floats In AT&T syntax, the source operand is listed…
When you install Fedora (or other Linux distributions) alongside Windows on a UEFI system, GRUB sometimes fails to generate a functional boot entry for Windows. The symptom is a missing or non-working “Windows Boot Manager” entry in the GRUB menu, or GRUB drops you to a shell prompt when you select it. Why This Happens…
Getting video files from your Linux machine to an iPhone for offline viewing doesn’t require iTunes or complex workarounds. Here are the practical methods that actually work in 2026. Quick Upload via VLC’s WiFi Interface VLC for iOS remains the most straightforward approach for occasional transfers. It’s free, open-source, and handles virtually any codec you…
When you need to completely wipe a USB drive on Windows, you have several reliable options. Choose based on your security requirements: Disk Management for quick reformatting, DiskPart for automation, or secure erasure tools if the drive contained sensitive data. Using Windows Disk Management The simplest built-in approach: Connect the USB drive Open Disk Management…
The most reliable way to download YouTube videos is yt-dlp, a maintained fork of youtube-dl that handles modern YouTube changes and DRM protections. It works on Linux, macOS, and Windows. Installation Linux (Debian/Ubuntu): sudo apt install yt-dlp Linux (Fedora/RHEL): sudo dnf install yt-dlp macOS: brew install yt-dlp Windows or any system with Python 3.8+: pip…
To replace text containing newline characters in Emacs, you need to insert actual newline characters in the replacement string rather than literal \n sequences. Using C-q C-j for interactive replacement The standard approach uses quoted-insert to insert special characters literally: C-q invokes quoted-insert C-j inserts a literal newline (LF, ASCII 10) Open the find and…
Emacs doesn’t restore your cursor to the last editing position by default—Vim does this out of the box. Fortunately, save-place-mode is built into Emacs and requires minimal configuration to enable this behavior. Basic Setup Add this to your ~/.emacs.d/init.el: (save-place-mode 1) That’s all you need. The mode automatically saves your cursor position when you close…
SSH tunneling and port forwarding work well for specific traffic, but they don’t give you a full VPN-like experience where all system traffic routes through the remote server. If you need transparent, system-wide traffic redirection over SSH, you have several solid options depending on your platform. sshuttle on Linux and macOS sshuttle is the standard…
The HTML5 <video> element is the standard for embedding video content without plugins. It’s supported across all modern browsers and provides native playback controls, accessibility features, and performance benefits. Basic Video Embedding The simplest approach uses the <video> element with a <source> tag: <video controls> <source src=”path/to/file.mp4″ type=”video/mp4″> Your browser does not support the video…
To mark text as deleted or struck through in BBCode, use the [s] tag: [s]strikethrough text[/s] This renders as strikethrough text with a horizontal line through the middle. Some platforms also support the longer [strike] alias: [strike]strikethrough text[/strike] Both tags are functionally equivalent — the choice depends on your platform’s BBCode parser. HTML Output and…
UDP packet loss on Linux commonly stems from undersized kernel buffers. When packets arrive faster than the application can process them, the kernel drops excess datagrams silently. Unlike TCP, UDP offers no retransmission, so these losses are permanent. Proper buffer tuning is essential for DNS servers, NTP, monitoring systems, video streaming, and any high-throughput UDP…
The fclose theme is a lightweight Question2Answer theme distributed as a set of PHP and CSS files. It provides a clean base layout that you can extend with custom styling and icon sets. Getting the Theme Files You need two core files to run fclose: qa-theme.php — The theme class that extends qa_html_theme_base and controls…
When processing text files or command output, non-printable ASCII characters corrupt formatting, break parsing, or create unexpected behavior. You need the right tool for your specific case — whether you’re stripping control characters, handling UTF-8, or cleaning up embedded escape sequences. Understanding Printable ASCII The standard printable ASCII range includes: Tab (hex 09) Line Feed…
systutorials.com runs on WordPress with the Twenty Fourteen theme (now legacy) and a custom Q2A installation for the Q&A section. If you’re rebuilding something similar, the approach differs between the two platforms. WordPress Theme Strategy If starting fresh today, Twenty Fourteen is outdated. Modern alternatives include: Twenty Twenty-Five — the current WordPress default, lightweight and…
The standard way to generate patches from git commits is git format-patch. This creates email-ready patch files that include commit messages, author information, and metadata. # Create a patch from the last commit git format-patch -1 # Create patches for the last N commits git format-patch -3 # Create patches from a specific commit onwards…
The simplest approach is passing log level flags directly to sbt: sbt –error “compile” sbt –warn “clean compile” sbt –info “test” sbt –debug “publishLocal” Common log level flags: –error — errors only –warn — warnings and errors (default) –info — info, warnings, and errors –debug — verbose debugging output –trace — most verbose, rarely needed…
awk is the most efficient approach for this task. It processes the file in a single pass and doesn’t load data into memory: awk ‘{ total += $5; count++ } END { print total/count }’ file.txt This assumes your numeric value is the 5th whitespace-delimited field. For a file like: Run 0: Time used: 22.235331711…
If you need millisecond precision timestamps from the command line, there are several approaches depending on your use case and system requirements. Using date with %3N The simplest and most reliable method on modern GNU coreutils (8.32+) is: date +%s%3N This outputs seconds since epoch followed by exactly three digits of nanosecond precision (milliseconds). Example…
When working with multiple Scala projects, you’ll often need different sbt versions. A project using sbt 1.9.x may not be compatible with sbt 0.13.x, and manually switching between system-wide installations becomes tedious and error-prone. Using sbt-extras for automatic version detection The most reliable approach is sbt-extras, a wrapper script that automatically detects and uses the…