Linux Tutorials and Command Line Guides

Install Velociraptor on Ubuntu 25.04: download the linux-amd64 binary, generate server.config.yaml, build the Debian server package, enable velociraptor_server, add a GUI admin user, open port 8000 for clients, and …

Remove LibreOffice from Ubuntu with apt purge or the libreoffice* wildcard, autoremove UNO and URE dependencies, delete ~/.config/libreoffice, uninstall from App Center, and confirm no dpkg or desktop leftovers remain.

Free disk space on Ubuntu with apt clean and autoremove, journalctl vacuum, BleachBit previews, and the Ubuntu Cleaner PPA; find large caches with du and Baobab before you delete anything.

Remove software on Ubuntu the right way: find the real package name, use apt remove or purge, uninstall Snap and Flatpak apps, clean rc config leftovers, avoid autoremove surprises, and delete manual installs from …

Install xoscope on Ubuntu from the universe apt package or build 2.3 from source; enable universe, pull GTK and ALSA dev libraries, work around SourceForge 404 and COMEDI API changes, launch the sound-card oscilloscope, …

Install Modoboa on Ubuntu with the official installer: DNS (MX, SPF, DKIM, DMARC, PTR), Let's Encrypt SSL, domains and mailboxes, webmail and Thunderbird setup, port 25 checks, and common troubleshooting.

Install OnlyOffice Desktop Editors on Ubuntu from the official download.onlyoffice.com APT repo, a direct .deb, Snap, or Flatpak: import the GPG key, install onlyoffice-desktopeditors 9.4, launch desktopeditors, and …

Remove Python 3.14 or 3.15 on Ubuntu 22.04 and 24.04 safely: uninstall Deadsnakes packages, delete source altinstall files, clean pyenv versions and venvs, and keep Ubuntu system python3 working.

Linux rm has no built-in undo and does not use Trash by default, but you can sometimes recover deleted files—stop writes to the disk first, then try backups, open file handles via /proc, carving tools like Foremost and …

Learn how to build an RPM package in Linux using rpmbuild. Create the rpmbuild directory structure, write a SPEC file, build RPM from source, create RPM from scratch, and verify the package.

Learn how to install fonts in Linux using the command line and GUI. Install TTF and OTF fonts for the current user or system-wide, update font cache, verify with fc-list, and uninstall fonts.

Understand various terminologies with linux memory management, dirty page, swapping, inactive, active memory, Translation Lookaside Buffers (TLB), page cache

Step-by-Step Tutorial to configure hugepages in red hat and centos 7/8 linux using vm nr_hugepages in /etc/sysctl.conf. Also configure hugepages pool using hugeadm

Learn how to check Transparent HugePages in Linux, verify if THP is enabled or disabled, understand AnonHugePages vs static hugepages, and find per-process THP usage.

Learn how to check if CPU supports HugePages with 2MB and 1GB Size in CentOS/RHEl 7 Linux and change default hugepage size permanently using GRUB2 with examples

Compare HugePages (static HugeTLB) and Transparent HugePages in Linux: what each is, when to use or disable them, how to check and configure them, how Kubernetes exposes hugepages-2Mi and hugepages-1Gi, and how to …

Even though containers are valuable in the current software development trends, realizing containerized deployments in organizations is not easy. This article

How to detect, capture and monitor memory leak in various applications such as C, C++ or in Linux process. use valgrind, core dump to capture leak information

Learn how to check memory usage by process in Linux with tested ps, top, pmap, /proc, smaps_rollup, statm, free, and pidstat examples. Understand RSS, VSZ, PSS, USS, shared memory, and how to find the top …

Learn how Linux enforces memory limits inside containers using cgroups, how cgroup v1 and v2 differ, why tools disagree, and how Docker and Kubernetes map limits to the kernel.

Learn how to change username in Linux with usermod, rename the home directory, update the primary group, verify UID/GID ownership, and fix common username rename errors safely.

Learn how to check sudo access in Linux. Check if you or another user has sudo privileges with sudo -l, test sudo access non-interactively in a bash script with sudo -n, and list all sudo users, with real tested output.

Learn how to check disk space in Linux from the command line. Use df to check free space, du to check disk usage by folder, and find what is eating your storage, with real tested output and fixes for "No space left on …

Understand CPU, processor, socket, core, thread, hyper-threading, CPU cache, frequency scaling and Linux commands like lscpu, nproc, mpstat and cpupower with validated output.

Learn how to set SFTP umask in Linux with OpenSSH internal-sftp, sftp-server, Match User, Match Group, chrooted SFTP users, and tested upload permission examples. Also understand Linux umask, why .bashrc umask does not …

Learn how to refresh network settings in Ubuntu after IP address, route, DNS, DHCP, Netplan, NetworkManager, or systemd-networkd changes. Includes safe remote-server workflow, tested verification commands, and practical …

Learn how to configure a VNC server on Ubuntu with TigerVNC, XFCE, a per-user VNC password, localhost-only binding, SSH tunneling, firewall checks, and a systemd service for persistent remote desktop access.

Learn how to backup and restore Brave Browser profile data on Linux, including settings, bookmarks, session files, cache, profile paths, tar archives, checksums, and safe restore steps.

Learn how to install a specific package version with apt or apt-get on Ubuntu and Debian, list available versions, simulate installs safely, handle dependency conflicts, and hold or unhold package versions.

Learn how to add a Linux user to the sudo group on Ubuntu and Debian, use the wheel group on RHEL-based systems, verify sudo access, and avoid confusing group-based sudo with custom sudoers file rules.