SSH is fast enough for most tasks, but when you’re transferring large files, running multiple commands, or managing hundreds of servers, every millisecond counts. Here’s how to squeeze real performance gains from SSH and SCP on Linux. Choose the Right Cipher Cipher selection has the biggest impact on throughput. Modern CPUs have AES-NI hardware acceleration,…
When you need to reach a server through one or more intermediate hosts, you can establish a direct connection without manually chaining SSH sessions. This is essential for accessing internal servers that aren’t directly reachable from your workstation. The scenario laptop —-> proxy —-> server You want to connect to server.example.com through proxy.example.com as if…
Hadoop uses three primary configuration files to define YARN, HDFS, and MapReduce behavior: HDFS: hdfs-site.xml YARN: yarn-site.xml MapReduce: mapred-site.xml These files live in $HADOOP_HOME/etc/hadoop/ and override the built-in defaults when present. Finding Official Default Values Apache publishes default configuration documentation for each release. For current versions: Hadoop 3.4.x (Latest) HDFS defaults: https://hadoop.apache.org/docs/r3.4.0/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml YARN defaults: https://hadoop.apache.org/docs/r3.4.0/hadoop-yarn/hadoop-yarn-common/yarn-default.xml…
The Windows (Super) key can be remapped to function as an additional Ctrl key, useful if you work across multiple systems or prefer the extra modifier. The approach varies significantly by display server and desktop environment. GNOME (Wayland and X11) GNOME 3.38 and later have built-in remapping through Settings: Open Settings → Keyboard → Special…
Custom headers and footers in Apache directory listings let you add branding, instructions, or navigation without modifying the core file listing. This is useful for public file archives, download directories, or any indexed directory you want to customize. Basic Setup with .htaccess Add these directives to .htaccess in the directory where you want custom listings:…
Remapping modifier keys on Linux makes sense if you’re an Emacs power user, prefer ergonomic hand positioning, or simply don’t use the Win key. The standard approach moves frequently-used modifiers closer to your thumbs by trading the underutilized Super/Win key for additional Ctrl or Alt access. A typical remapped layout looks like: |Ctrl|Alt|Ctrl| Space Bar…
When you’ve modified your keyboard layout or key bindings using xmodmap and need to revert to the default, setxkbmap is your primary tool. However, the approach depends on whether you’re running X11 or Wayland, and what aspects of the configuration you want to reset. Check Your Session Type Before attempting any resets, verify whether you’re…
The split command is the standard tool for breaking large text files into smaller chunks on Linux. Here’s the basic syntax: split -l 1024 content.txt splitted-content.txt- This creates output files named splitted-content.txt-aa, splitted-content.txt-ab, and so on, with each containing 1024 lines. Understanding output naming By default, split appends two-character suffixes starting with aa. The naming…
Memory leak detection is critical for C program reliability. Several tools work at different stages of development—compile time, runtime, and production scenarios. Your choice depends on performance tolerance, integration needs, and how much detail you require. AddressSanitizer (ASan) AddressSanitizer is the first tool to reach for in 2026. It’s compiler-integrated, fast, and catches a broader…
Remapping space to Ctrl while preserving space on tap is useful for modal editors and power users. The challenge: distinguish between a held key (Ctrl) and a quick tap (space). Kernel-level remapping can’t do this, so you need userspace solutions. Quick Comparison of Methods Tool Best For Pros Cons keyd Simplicity, both X11 and Wayland…
Emacs makes heavy use of Ctrl, and many users find it ergonomically difficult to hit Ctrl repeatedly, especially on modern keyboards where Ctrl is placed far from home row. Swapping Alt and Ctrl can make Emacs navigation more comfortable. This guide covers modern approaches for different desktop environments and input systems. Emacs-Only Configuration (Simplest) If…
GNOME’s default Alt-Tab behavior switches between applications, grouping all windows from the same app together. If you work with multiple windows in a single application—multiple browser tabs, text editors, or terminals—this becomes frustrating. Here’s how to change it to window-based switching. Using the Alternate Tab Extension The simplest approach is enabling GNOME’s built-in Alternate Tab…
Remapping Caps Lock to Control is a worthwhile investment if you spend significant time in Emacs or vim. Your pinky will benefit from years of reduced strain. Desktop Environment Settings (Easiest) Most modern desktop environments include a built-in option for this remapping. GNOME (40+): Open Settings → Keyboard → Special Character Options Toggle “Make Caps…
dd is a powerful utility for reading and writing raw data to block devices. While it’s a Linux standard, you have several options for using it on Windows systems. WSL2: The Modern Approach For Windows 10 (21H2+) and Windows 11, Windows Subsystem for Linux 2 (WSL2) is the best choice. It provides a full Linux…
When gthumb hangs during startup after connecting an iPhone, external drive, or other USB device, the issue typically stems from gthumb attempting to enumerate mounted storage devices during initialization. Certain filesystem states, permissions misconfigurations, or slow I/O can cause the process to block indefinitely. Quick fix: unmount the device The most straightforward solution is to…
If you want Emacs to run in the terminal without opening an X window, you have several practical options depending on your setup and workflow. Option 1: Install emacs-nox (Recommended for servers) The cleanest approach is installing the no-X variant of Emacs, which is built without X11 support. This reduces memory overhead and startup time…
If you need to boot Windows from the GRUB2 command line—whether during troubleshooting, recovery, or when your boot configuration is broken—you can do it with a few commands. This guide covers both BIOS and UEFI systems. Quick boot for BIOS systems Assuming Windows is installed on the first partition of the first disk in NTFS…
If you’re working with legacy BIOS systems and MBR partition tables, Fedora’s installer can sometimes misdetect your firmware mode and attempt UEFI/GPT setup on hardware that only supports legacy BIOS. This guide covers the proper approach for Fedora 39+ on MBR systems. Prerequisites Before starting, verify your system configuration: Boot the installer in legacy BIOS…
When you need to identify which package installed a command on your Fedora system, you have several reliable methods depending on whether the package is already installed. Quick lookup for installed commands The fastest approach combines which to locate the command with rpm to query the owning package: $ rpm -qf $(which ping) iputils-8.40-4.fc40.x86_64 The…
When network interfaces fail or behave unexpectedly, you need to inspect driver details, hardware state, and kernel messages. Here’s the practical toolkit for diagnosing network hardware and driver issues. Kernel Messages and Logs Start by checking kernel logs where driver initialization and errors are recorded: dmesg | grep -i network dmesg | grep -i driver…