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…
Accessing a remote desktop environment on a Linux server securely requires proper tunneling. While SSH X11 forwarding works for single applications, VNC provides a full graphical desktop session. By combining VNC with an SSH tunnel, you encrypt all traffic and can work around firewall restrictions that only allow port 22. Why VNC Over SSH? VNC…
MPlayer is largely unmaintained; mpv is the actively developed fork that handles 95% of these commands with compatible bindings. That said, if you’re still running MPlayer or need legacy support, here’s what you need to know. MPlayer uses a fully configurable keyboard control layer. Most of these shortcuts work in mpv as well, though some…
This article documents performance benchmarks for Xen virtualization, comparing CPU and memory performance between Dom0 (privileged domain), DomU (unprivileged guest), and bare metal. While Xen remains in production use (AWS EC2, Citrix Hypervisor, Oracle Cloud), most Linux distributions default to KVM for new deployments. For contemporary virtualization needs, evaluate both Xen and KVM based on…
Desktop clients for WordPress have largely fallen out of favor in recent years, but they still serve a niche purpose for users who prefer offline writing and batch publishing. Lekhonee was one such tool — a GNOME-based WordPress client that provided a lightweight alternative to the web interface. Important context: Lekhonee is no longer actively…
Fedora 中文字体的显示一直是个常见问题，特别是在英文环境中。通过合理的字体配置，可以获得清晰舒适的中文显示效果。本文介绍的方案使用开源字体，这些字体在 Fedora 的标准仓库中都可以获得。 快速配置 如果你只想快速完成配置，运行以下命令： sudo dnf install cjkuni-ukai-fonts cjkuni-uming-fonts sudo wget https://raw.githubusercontent.com/zma/config_files/master/others/local.conf \ -O /etc/fonts/local.conf 这会安装文鼎楷体和文鼎明体，并配置字体渲染优先级。注销后重新登录即可生效。 推荐字体包 Fedora 仓库中提供了多个中文字体包： 基础中文字体： # 文鼎明体 — 适合正文阅读，清晰度高 sudo dnf install cjkuni-uming-fonts # 文鼎楷体 — 适合标题和打印 sudo dnf install cjkuni-ukai-fonts Google Noto 字体（推荐）： # Noto Sans CJK — 现代、清晰、覆盖全面 sudo dnf install google-noto-sans-cjk-fonts # Noto Serif CJK…
Git and SSH integrate seamlessly for version control infrastructure. An SSH-based Git server works well for small teams where all members are trusted and have administrator-level access to all repositories. This approach is straightforward to deploy, but lacks fine-grained access control. For teams that need role-based repository access or audit trails, consider dedicated tools like…
Configuring proper Chinese character rendering in Fedora requires attention to font selection and system settings. This guide covers configuration for contemporary Fedora/RHEL systems where you run an English locale but need reliable Chinese character display. Font Selection You have several solid open-source options for Chinese fonts. Each has different characteristics suited to different use cases….
Customizing your desktop environment to match macOS aesthetics remains popular on Linux, though the approach differs significantly from GNOME 2 era configurations. Modern desktop environments like GNOME (40+) and KDE Plasma (5/6) use different theming systems, but achieving an Apple-inspired look is still straightforward. Current Desktop Environment Options GNOME 40+ uses CSS-based theming and GTK…
Split the current window horizontally: Ctrl-W Ctrl-S Switch between windows: Ctrl-W Ctrl-W ” toggle to next window Ctrl-W j ” move to window below Ctrl-W k ” move to window above Ctrl-W h ” move to window left Ctrl-W l ” move to window right Rotate window positions: Ctrl-W Ctrl-R ” rotate clockwise Ctrl-W Ctrl-X…
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 —…
After running on MediaWiki, we migrated back to WordPress. Both platforms have their strengths, but WordPress proved to be the better fit for our site’s goals. What WordPress Does Better for This Site Plugin Ecosystem and Content Discovery WordPress’s plugin landscape is significantly deeper than MediaWiki’s. The YARPP (Yet Another Related Posts) plugin and its…
File compression is a routine task in Linux administration. You’ll encounter several tools, each with different tradeoffs between compression ratio, speed, and compatibility. This guide covers the most common compression formats: gzip, bzip2, 7z, xz, and zip. The examples below assume you’re compressing a directory called dir. Each tool supports compression level options — you…
TeraSort is Hadoop’s standard benchmark for measuring distributed sorting performance across clusters. It consists of three components: TeraGen generates random input data, TeraSort performs the distributed sort, and TeraValidate confirms the output is globally sorted. Modern Hadoop deployments typically run on Hadoop 3.x or higher, with improvements in YARN resource management, better performance tuning options,…
Hadoop 1.x reached end-of-life in 2014 and is no longer maintained. This post documents a deprecated architecture for historical reference only. For new deployments, use Hadoop 3.x+ with YARN, which offers significant improvements in resource management, multi-tenancy, and reliability. See the Apache Hadoop documentation for current versions. For managed services, consider AWS EMR, Google Dataproc,…
Gitosis is unmaintained and shouldn’t be used for new deployments. Use Gitolite or Forgejo instead. This guide covers Gitolite, which provides fine-grained access control, is actively maintained, and handles multiple repositories under a single system user. Prerequisites A server running Linux (Debian, Ubuntu, CentOS, or similar) SSH access to the server with sudo privileges A…
Hadoop daemons communicate over specific TCP ports that you’ll need to know for cluster setup, firewall configuration, and application development. These ports are configurable but come with sensible defaults in Hadoop 3.x. HDFS Ports Service Port Configuration Property Purpose Namenode HTTP UI 9870 dfs.namenode.http-address Web UI and metadata operations Namenode HTTPS UI 9871 dfs.namenode.https-address Secure…
Running benchmarks after a Hadoop installation helps validate that your cluster works correctly and gives you baseline performance metrics. The Sort benchmark is a standard test that exercises the MapReduce execution engine and HDFS, making it useful for stress-testing both the distributed storage layer and computation framework. What the Sort Benchmark Does The Sort benchmark…
Hadoop 3.x remains the current stable version with YARN improvements, HDFS federation, and erasure coding. Hadoop 1.x and 2.x are no longer maintained. For new deployments, evaluate whether Hadoop fits your needs or if managed services like AWS EMR, Google Dataproc, or Azure HDInsight better suit your infrastructure. This post covers common configuration mistakes and…
Hadoop’s default configuration runs in standalone (local) mode as a single JVM process — no HDFS daemons, no YARN, no distributed overhead. This mode is useful for development, testing MapReduce jobs, and debugging before moving to a clustered deployment. For new deployments, evaluate whether you need Hadoop at all. Consider cloud-native alternatives like AWS EMR,…