Note: This post covers Git basics or gitolite/gitosis setup. Core Git commands remain valid. For modern Git workflow tools, see Git documentation or hosted solutions like GitHub, GitLab. I ever introduced seting up git server using SSH or gitosis. However, gitolite is the way to go for managing git servers if you want an lightweight…
Outdated Guide: This guide covers Fedora which reached end-of-life many years ago. For current Fedora docs, visit Fedora Docs. Core concepts remain applicable but package names and paths may differ. Outdated Guide: This guide covers Fedora which reached end-of-life many years ago. For current Fedora docs, visit Fedora Docs. Core concepts remain applicable but package…
Note: This post covers NFS server and client setup. Core NFS concepts remain valid. NFSv4 with Kerberos is recommended for modern deployments. See Arch Wiki NFS for current best practices. Note: This post covers NFS server and client setup. Core NFS concepts remain valid. NFSv4 with Kerberos is recommended for modern deployments. See Arch Wiki…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. If /etc/fstab file is created with errors or the hardware configuration changes such as adding hard disks, Linux will boot into failure state. We can bypass the fstab failure by adding booting parameters to…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. In Linux, we use passwd to change password, but passwd requires input from stdin to get the new password. It is common case that we may want…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. xclip is a tool to copy the copy the output of commands from a command line in a terminal to X selection or clipboard. It connects the…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Automatic keyboard pressers are useful tools. However, it seems that there is no simple and easy to use automatic keyboard presser for Linux if you search for…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Symbolic link or soft link files are very common and useful on Linux/Unix systems. It works as a alias file for a file. You can create a…
Note: This post covers C/C++ programming and debugging fundamentals. Core concepts remain valid. For current references, see cppreference.com and GDB documentation. Integers are natively supported in Bash shell. However, what if we use floating point in Bash shell? The short and direct answer is using ‘bc‘ command – “An arbitrary precision calculator language.” Just run…
Shutting Down All Xen VMs on a Server 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…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. I frequently run some commands/scripts on a batch of servers whose IPs are already collected in a file. I usually use a simple loop and call the…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. With a list of servers, it is common that one or more are down or crash. Lots cluster management tools can detect the aliveness of servers. However,…
Installing Scala on Linux 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…
Creating Patches with diff 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…
Installing mupdf 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…
Xen Domain-U Installation with PXE Booting 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…
About iptables vs firewalld 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…
Changing Systemd Targets on Fedora Linux 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…
Setting MATE as Default Desktop Environment for startx on Fedora 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…
MTU Configuration for WiFi Performance on Linux 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,…