Insert the installation media and create a mount point: sudo mkdir -p /media/dvd sudo mount /dev/sr0 /media/dvd For a DVD image file instead of physical media: sudo mount -o loop /path/to/image.iso /media/dvd Verify the mount and check that packages exist: ls /media/dvd/Packages/ | head On systems with automatic mounting (systemd-based), the DVD may already be…
When managing multiple servers, you need reliable ways to verify which hosts are reachable. While orchestration tools like Kubernetes and Ansible handle monitoring at scale, a lightweight Bash script works well for quick spot checks, operational tasks, or smaller deployments. Basic ICMP Reachability Check The simplest approach uses ping to test ICMP reachability: ping -W…
Running the same command across dozens of servers is a routine task in infrastructure work. Whether you’re checking disk usage, deploying updates, or gathering system metrics, doing this manually wastes time and introduces errors. The straightforward approach: iterate through a list of hosts and execute commands via SSH on each one. Basic Shell Loop Approach…
When managing Xen Dom0 hosts, shutting down guest VMs (DomUs) before powering off the physical server is essential to prevent data loss and filesystem corruption. Modern Xen distributions (including Citrix Hypervisor and AWS infrastructure) still rely on this principle, though the tooling has evolved. Using xl for VM Shutdown Current Xen installations use xl rather…
Scala runs on the Java Virtual Machine, so you’ll need Java 11 or later installed first. Check your current version: java -version If you don’t have Java installed, install it through your distribution’s package manager or use a tool like SDKMAN. Installing via SDKMAN (Recommended) SDKMAN is the most reliable way to manage Scala and…
Emacs provides a built-in tutorial. Access it with: C-h t For structured learning, the GNU Emacs Manual (built-in via C-h i) is the most authoritative resource. The Emacs Wiki also maintains community-driven guides and examples. Emacs configuration Store your configuration in ~/.emacs.d/init.el rather than the legacy ~/.emacs file. This keeps your Emacs directory cleaner and…
The mupdf package is available in most major Linux distributions. On RHEL/CentOS/Fedora: sudo dnf install mupdf mupdf-tools On Debian/Ubuntu: sudo apt install mupdf On Arch: sudo pacman -S mupdf mupdf is a lightweight, fast PDF and XPS viewer written in C. It’s significantly faster than heavier alternatives like Evince or Okular, making it ideal for…
The diff utility generates unified diffs that show changes between file versions. Always use the -u flag to create unified diffs, which are the standard format for patches. For a single file: diff -u original.c new.c > fix.patch For an entire directory tree: diff -rupN original/ new/ > patchfile.patch The flags break down as: -r:…
Qt and GTK applications often use different cursor themes, which creates visual inconsistency across your desktop. This mismatch is common in mixed-DE environments where Qt applications (like VLC, KeePass, or Telegram) inherit the wrong cursor style from system defaults. How Qt finds cursor themes Qt applications read cursor configuration from ~/.icons/default/index.theme. This file specifies which…
The startx command launches an X session without a display manager, reading configuration from $HOME/.xinitrc. By default, this file doesn’t exist—startx falls back to system defaults that typically only recognize GNOME or KDE. If you’ve installed MATE and want to use it with startx, you need to create a user-level configuration. Understanding startx Initialization When…
Fedora switched to systemd for service management years ago, replacing the traditional /etc/inittab file with a target-based system. While systemctl set-default is the standard approach, understanding the manual method gives you insight into how systemd actually manages boot targets. Systemd Targets vs. Legacy Runlevels Systemd uses targets instead of runlevels. The two primary targets you’ll…
Modern Fedora (29+) uses firewalld by default instead of the legacy iptables service. If you’re working with an older system or one configured for iptables, the concepts here still apply, but you should first check what’s actually managing your firewall: systemctl status firewalld systemctl status iptables If firewalld is active, use firewall-cmd instead. For iptables-based…
Xen remains in production use across cloud providers (AWS EC2, Citrix Hypervisor) and large infrastructure deployments, though KVM has become the default hypervisor for most Linux distributions. This guide covers installing a Fedora Domain-U on a Xen Dom0 using PXE boot, applicable to current Fedora releases. Prerequisites A working Xen Dom0 installation LVM backing store…
Modern Linux systems use GRUB2 as the bootloader. You’ll set the default boot entry either through the configuration file or via command-line tools. View Available Boot Entries First, list all available GRUB2 menu entries: grep ^menuentry /etc/grub2.cfg | cut -d “‘” -f2 On UEFI systems, use /etc/grub2-efi.cfg instead. If you’re unsure which mode your system…
Xen remains relevant for certain production workloads, particularly in cloud infrastructure (AWS EC2, Citrix Hypervisor) and enterprise environments requiring strong VM isolation. However, most Linux distributions now default to KVM for virtualization due to simpler setup and broader ecosystem support. If you’re evaluating hypervisors, consider KVM or container-based solutions like Podman and Kubernetes for new…
Copying text to a file is a common operation on Linux, and there are several approaches depending on your workflow. Opening an editor like vim or nano works fine, but for quick pastes there are faster methods worth knowing. The Quick Clipboard Method If you have text copied to your clipboard, the fastest way to…
If your Linux machine is getting noticeably slower WiFi speeds than other devices on the same network, MTU (Maximum Transmission Unit) misconfiguration can be a culprit. While MTU tuning won’t be the answer in every case, it’s worth investigating if you’re seeing symptoms like high latency, dropped packets, or intermittent connection issues. Understanding MTU MTU…
If you need to work with Office files (.doc, .docx, .xls, .ppt) on Linux, Wine can run Microsoft Office 2007, though this approach has largely been superseded by cloud-based alternatives and native Linux tools. That said, for specific compatibility requirements, here’s how to set it up. Install Wine First, install Wine. Most distributions now package…
Start by identifying your optical drive device. List your CD/DVD drives: ls -l /dev/cdrom This typically shows a symlink to your actual device: lrwxrwxrwx. 1 root root 3 Aug 1 17:00 /dev/cdrom -> sr0 You can also check active optical drives with lsblk: lsblk | grep -i rom Modern systems may use /dev/sr0, /dev/sr1, etc….
Every file on Linux consumes an inode. When you exhaust your inode allocation, you can’t create new files even if disk space remains. This is a real constraint on systems handling millions of small files—email servers, web caches, log rotators, container registries. Quick inode checks Check overall filesystem inode usage: df -i This shows inodes…