When GitBook or other tools call Calibre’s ebook-convert command on a headless server, you’ll hit this error: RuntimeError: X server required. If you are running on a headless machine, use xvfb This happens because Calibre needs an X11 display server, even though you’re just converting files. The solution is to wrap ebook-convert with xvfb-run, which…
When your host machine connects to the network via WiFi, giving QEMU guests network access requires a different approach than traditional bridged networking. Since wireless interfaces typically don’t support bridge mode, you’ll need to use NAT (Network Address Translation) or a tap device with masquerading. Understanding your options NAT mode is the simplest approach—the host…
In HDFS, files are split into blocks and replicated across multiple DataNodes for fault tolerance and parallelism. When you need to know exactly which DataNodes hold a specific file’s blocks, use hdfs fsck with the -locations and -blocks flags. Basic command hdfs fsck /path/to/file -files -locations -blocks This queries the NameNode and returns the block…
HDFS uses the dfs.replication property in hdfs-site.xml to set a global default replication factor for all blocks. However, you can override this on a per-file or per-directory basis using the hdfs dfs -setrep command — useful for frequently accessed “hot” files that need higher availability. Basic syntax hdfs dfs -setrep [-R] [-w] <numReplicas> <path> Setting…
When processing application logs (like Hadoop/log4j output), you often need to extract entries from a specific time window. This is especially common in automated routines that run periodically—for example, pulling the last 4 hours of logs every 4 hours via cron. Log format considerations Most application logs follow a consistent timestamp format. For example, log4j…
Maildir is a common email storage format on Linux servers and is widely supported by mail clients and delivery agents. Here’s how to access and read your mail stored in Maildir format. Using Mutt Mutt is a lightweight terminal-based email client that handles Maildir natively. To open a Maildir folder: mutt -f /path/to/maildir/ For example,…
The .mbox format stores email messages as plain text in a single file, with each message separated by a “From ” line. If you have archived emails or need to work with mailbox exports, here are the practical ways to read and manipulate them on Linux. Using Thunderbird Thunderbird remains a solid option for viewing…
A user’s UID (User ID) is a unique numerical identifier in Linux. You’ll need to check or modify UIDs when migrating systems, fixing permission issues, or managing user accounts across multiple machines. Finding a user’s UID To check a user’s UID, use the id command: id -u username This returns just the numeric UID. For…
The primary tool for iPhone backups on Linux is libimobiledevice, a cross-platform library that communicates with iOS devices without iTunes. It works with modern iOS versions (iOS 7 through current releases) and supports encrypted backups. Installation On Debian/Ubuntu: sudo apt install libimobiledevice6 libimobiledevice-tools On Fedora/RHEL: sudo dnf install libimobiledevice libimobiledevice-devel On Arch: sudo pacman -S…
Package managers on Debian and Ubuntu systems maintain detailed logs of all installations, upgrades, and removals. These logs are essential for auditing system changes, troubleshooting dependency issues, or understanding what was installed and when. Log File Locations The main log files you’ll work with are: /var/log/dpkg.log — Low-level package management operations logged by dpkg /var/log/apt/history.log…
Linux Mint’s Driver Manager makes installing proprietary wireless drivers straightforward, but the process varies depending on your hardware and kernel version. For older HP Mini 110 netbooks with Broadcom BCM43xx chipsets, the bcmwl-kernel-source driver remains the most reliable option. Check Your Wireless Hardware First, identify your wireless adapter before installing drivers: lspci | grep -i…
Managing display power and screen blanking on Linux systems is essential for reducing power consumption on servers, headless machines, and workstations. Two primary tools handle this: setterm for software-based blanking and vbetool for hardware power management via VESA DPMS. Screen Blanking with setterm The setterm command controls when and how the console screen blanks during…
Monitoring hardware temperatures is essential for laptop health and performance. On Linux, lm-sensors provides CPU and system temperatures, while smartctl (from smartmontools) gives you drive health data including temperature readings. Installation Debian/Ubuntu/Linux Mint: sudo apt install lm-sensors smartmontools Fedora/RHEL/CentOS: sudo dnf install lm_sensors smartmontools Arch Linux: sudo pacman -S lm_sensors smartmontools Detecting Sensors Before reading…
Linux Mint defaults to graphical mode, but you can boot directly to the console if you prefer a text-only environment or need to troubleshoot display issues. There are two main approaches: using GRUB parameters or disabling the display manager entirely. Method 1: Add the text kernel parameter (GRUB) This is the quickest approach and keeps…
Adobe Reader (acroread) is rarely the best choice for Linux users anymore. It’s unmaintained, doesn’t receive security updates, and performs poorly compared to modern alternatives. This guide covers better options and how to set up a functional PDF viewer on Linux Mint. Why Not Adobe Reader? Adobe stopped supporting Reader for Linux in 2013. The…
iPhone videos often have rotation metadata embedded in the file rather than actual video frame rotation. This causes playback issues on Linux systems that don’t properly read the metadata. You’ll need to either apply the rotation during playback or permanently rotate the video frames. Understanding iPhone Video Rotation iPhones store rotation information in the video…
If you installed Linux in BIOS (Legacy) mode but need to boot alongside Windows in UEFI mode, converting an existing installation is possible but complex. This guide covers the process for modern systems while preserving your existing Linux installation and Windows setup. Before starting: Back up your data. This procedure involves disk partitioning and bootloader…
The most straightforward way to identify which installed package provides a specific file is with dpkg: dpkg -S /path/to/the/file The -S flag searches for a filename pattern across all installed packages. This works for any file path in your system, whether it’s a binary, library, configuration file, or anything else. Searching for command binaries To…
Linux Mint uses the APT package management system (derived from Debian). There are several straightforward methods to verify whether a specific package is installed. Using dpkg The dpkg command directly queries the package database on your system. dpkg -l | grep ghostscript This lists all installed packages and filters for ghostscript. If the package is…
Converting FLV files to MP4 is straightforward with FFmpeg. The basic command takes just seconds: ffmpeg -i input.flv output.mp4 FFmpeg will automatically select suitable video and audio codecs for MP4 format. This works for most FLV files without additional configuration. Preserving original quality If you want to skip re-encoding and copy the streams as-is, use…