SSH performance is constrained by cipher choice, especially for large file transfers over high-bandwidth links where CPU becomes the bottleneck. Selecting the right cipher, key exchange algorithm, and compression settings can yield substantial throughput improvements. Current Cipher Landscape Modern OpenSSH (7.4+) has deprecated or removed weak ciphers. Here’s what’s viable today: Secure and performant: chacha20-poly1305@openssh.com…
NFSv3 uses multiple RPC services, each requiring its own port assignment. Without explicit configuration, rpcbind assigns random high ports to four critical services, making firewall rules unmaintainable. Modern deployments should prioritize NFSv4 with Kerberos, but legacy NFSv3 environments remain common enough to warrant proper port management. The NFS service stack includes seven RPC programs: Service…
UDP (User Datagram Protocol) defined in RFC 768 provides a lightweight alternative to TCP. Unlike TCP’s stream-oriented approach, UDP delivers discrete packets — each recvfrom() or recvmsg() call returns one complete datagram. The tradeoff is real: you gain speed and lower overhead, but lose automatic reliability guarantees. Your application must handle packet loss, reordering, and…
Measuring time accurately matters for performance profiling, benchmarking, and latency-sensitive applications. Linux provides several APIs with different tradeoffs in resolution, overhead, and reliability. Understanding which to use prevents subtle bugs in production code. POSIX Time APIs: gettimeofday and clock_gettime gettimeofday() and clock_gettime() are the standard POSIX calls for reading system time. gettimeofday() returns seconds and…
John Ousterhout, a professor of computer science at Stanford, maintains a collection of “Favorite Sayings” grounded in decades of building real systems—RAMCloud, Tcl, and extensive work in distributed systems. These aren’t abstract principles. They’re lessons that apply directly to the work of building, debugging, and shipping software at scale. Optimize After Measurement, Not Before The…
MediaWiki stores its main page configuration in the MediaWiki:Mainpage system message. By default, this points to “Main Page”, but you can change it to any title that suits your wiki’s purpose. This process involves updating the system message, creating your new homepage, and handling redirects properly to avoid breaking external links and SEO. Step 1:…
MediaWiki’s sidebar is managed through the MediaWiki:Sidebar special page, a simple text-based system that controls navigation for your entire wiki. Changes take effect immediately across all pages. Accessing the Sidebar Configuration Navigate to the sidebar editor using one of these methods: Direct URL (replace example.com with your domain): With pretty URLs: https://example.com/w/MediaWiki:Sidebar Without pretty URLs:…
Modern MediaWiki installations should prioritize responsive design, but you may still need explicit device-based skin switching for specific use cases. This guide covers both approaches and how to implement them correctly. Responsive Skins: The Recommended Approach The default solution is using a responsive skin that adapts automatically to screen size without separate configuration. Vector 2022…
MediaWiki’s default URL structure — www.example.com/w/index.php?title=TITLE — works functionally but creates poor SEO signals and awkward shareable links. Clean URLs like www.example.com/w/TITLE improve search visibility, readability, and user experience while making pages easier to reference. LocalSettings.php Configuration Open LocalSettings.php in your MediaWiki root directory and add these settings: $wgScript = “/w/index.php”; $wgArticlePath = “/w/$1”; The…
Make is a build automation tool that reads configuration files (makefiles) to compile programs and manage project workflows. It’s been a standard in Unix/Linux development for decades and remains essential for managing builds where dependencies matter. Make works by defining targets and their dependencies, then specifying commands to build each target. When you run make,…
OCaml is a practical functional language with strong static typing and pattern matching. If you’re coming from systems programming or looking to add functional paradigms to your toolkit, these resources will accelerate your learning. Primary Learning Resources Real World OCaml by Yaron Minsky, Anil Madhavapeddy, and Jason Hickey remains the standard reference for modern OCaml…
KDE Plasma 6 provides straightforward touchpad configuration through the graphical Settings interface, with optional command-line customization for advanced cases. GUI Configuration Navigate to System Settings → Input Devices → Touchpad. You’ll find the “Tap to Click” toggle under the “Tapping” section. Enable it to map single-finger taps to left-button clicks. Additional options here include: Tap-and-drag:…
Use fdisk or parted to create a new partition. parted is generally preferred for modern systems as it handles larger disks better: # parted /dev/sdd (parted) mklabel gpt (parted) mkpart primary 0% 100% (parted) quit Or with fdisk for MBR-based systems: # fdisk /dev/sdd Then: Press n to create a new partition Press p for…
LVM (Logical Volume Manager) lets you combine multiple physical disks into flexible storage pools. This guide covers creating a volume group from multiple disk partitions—a common setup for servers that need flexible storage allocation across Xen guests, databases, or other demanding workloads. Prerequisites This assumes you have two or more unformatted disk devices available. In…
GNOME has hidden a few playful easter eggs in its desktop environment over the years. Two of the most well-known are “Free the Fish” and “Wanda the Fish” — small animated features that surprise unsuspecting users. Free the Fish (GNOME 2) In GNOME 2, pressing Alt+F2 and running this command: free the fish releases a…
tmpfs delivers exceptional I/O performance since it lives entirely in RAM. Exporting it via NFS can be useful for temporary caches, build artifacts, or high-speed data sharing between systems on a trusted network. The catch: NFS needs additional configuration to export pseudo-filesystems like /dev/shm. Without the right settings, you’ll hit access denied errors or fsid…
ffmpeg is the de facto tool for desktop recording on Linux. It can capture your X11 or Wayland display and encode directly to MP4, WebM, or other formats without requiring intermediate files. Basic X11 Screen Capture For X11-based desktops (KDE Plasma, XFCE, i3, etc.), use the x11grab input device: ffmpeg -f x11grab -s 1920×1080 -r…
Guake is a drop-down terminal emulator for GNOME that brings the Quake-style console experience to Linux desktops. When you press a hotkey (F12 by default), a terminal slides down from the top of the screen. Press it again and it retracts. It’s fast, minimal, and designed purely around keyboard efficiency. Installation On Fedora/RHEL-based systems: sudo…
This post analyzes I/O performance between loopback and blktap backends for Xen file-backed virtual block devices (VBDs), based on testing from 2013. While Xen remains in production use (AWS EC2, Citrix Hypervisor), most Linux deployments now default to KVM. For modern virtualization needs, consider KVM/libvirt or container solutions like Docker and Kubernetes. This post is…
Modern GNOME uses dconf as its configuration backend, replacing the older GConf system. Whether you’re managing a single workstation or deploying across multiple systems, understanding dconf and gsettings is essential for customizing GNOME environments efficiently. Understanding the Configuration Stack GNOME’s configuration hierarchy works like this: dconf — the low-level database storing all settings gsettings —…