4.1 Linux administration

19 entries

• 0099 Proxmox VE repositories and updates: enterprise vs no-subscription A fresh Proxmox VE install uses the enterprise repository, which needs a subscription. Learn how to switch to the no-subscription repository and… Beginner · How-to · Linux Article Installation & first steps · Packages & updates 15 Oct 2026
• 0102 Proxmox VE storage types: local, LVM-thin, ZFS, NFS and Ceph Proxmox VE stores disks, ISOs, templates and backups in storage pools defined in /etc/pve/storage.cfg. Learn the main storage types, what local and… Intermediate · Concept · Linux Article Disks, LVM & filesystems · Storage 15 Oct 2026
• 0103 Proxmox VE networking: Linux bridges (vmbr0) and VLANs Guests reach the network through Linux bridges such as vmbr0, defined in /etc/network/interfaces. Learn the default setup, VLAN-aware bridges, VLAN tags for… Intermediate · How-to · Linux Article Installation & first steps · Networking & firewalls 15 Oct 2026
• 0164 systemd services: systemctl and journalctl basics systemd starts and supervises services on most Linux servers. systemctl starts, stops and enables them; journalctl shows their logs. Beginner · Concept · Linux Article Services & systemd 15 Oct 2026
• 0165 Write a systemd service unit for your own app Turn any long-running program into a proper service: create a unit file, run it as an unprivileged user, restart it on failure… Intermediate · How-to · Linux Article Services & systemd 15 Oct 2026
• 0166 Replace a cron job with a systemd timer A systemd timer runs a service on a schedule like cron, but logs every run to the journal, can catch up missed… Intermediate · How-to · Linux Article Services & systemd 15 Oct 2026
• 0167 Fix: Job for nginx.service failed because the control process exited with error code systemctl prints this when a service's start command exits with an error. The real reason is in journalctl; for nginx it is… Intermediate · Fix · Linux Article Networking & firewalls · Services & systemd 15 Oct 2026
• 0169 Add a new disk: partition, format and mount it by UUID Find a new disk with lsblk, partition it with parted, create an ext4 or XFS filesystem and mount it permanently through /etc/fstab… Intermediate · How-to · Linux Article Disks, LVM & filesystems 15 Oct 2026
• 0170 LVM explained: physical volumes, volume groups and logical volumes LVM puts a flexible layer between disks and filesystems, so you can grow volumes, add disks and take snapshots without repartitioning. Intermediate · Concept · Linux Article Disks, LVM & filesystems 15 Oct 2026
• 0172 Fix: No space left on device Writes fail because a filesystem is full, out of inodes, or holding space for deleted files that are still open. Find which… Beginner · Fix · Linux Article Disks, LVM & filesystems 15 Oct 2026
• 0173 Set a static IP address: nmcli on RHEL vs netplan on Ubuntu RHEL, Rocky and AlmaLinux configure networking with NetworkManager (nmcli); Ubuntu Server uses netplan YAML. Here is the same static IP setup in… Intermediate · How-to · Linux Article Networking & firewalls 15 Oct 2026
• 0174 Network and DNS troubleshooting commands: ip, ss, dig, resolvectl A layer-by-layer cheat sheet for "the server cannot reach X": interfaces and routes with ip, listening ports with ss, and name resolution… Beginner · Reference · Linux Article Networking & firewalls 15 Oct 2026
• 0175 Open ports with firewalld and ufw firewalld (RHEL, Rocky, AlmaLinux) and ufw (Ubuntu) are friendly front ends to the kernel firewall. Allow SSH first, then open only the… Intermediate · How-to · Linux Article Networking & firewalls 15 Oct 2026
• 0176 apt vs dnf: package commands and automatic security updates The everyday package commands on Debian/Ubuntu (apt) and RHEL/Rocky/Alma (dnf) side by side, plus how to turn on automatic security updates on… Beginner · Reference · Linux Article Packages & updates 15 Oct 2026
• 0177 Users, groups and sudo on Debian, Ubuntu and RHEL How Linux accounts and groups work, how to create users, and how sudo gives admin rights through the sudo group on Debian/Ubuntu… Beginner · Concept · Linux Article Users, sudo & hardening 15 Oct 2026
• 0193 Linux logs reference: journalctl, journald storage, logrotate and centralized logging Read and filter systemd journal logs, keep their disk use in check, rotate classic log files with logrotate, and understand when to… Intermediate · Reference · Linux Article Linux administration · Logs 15 Oct 2026
• 0249 Set up and harden a fresh Linux server in one afternoon Take a new Ubuntu, Debian or Rocky/Alma server from first login to a safer baseline: sudo admin, SSH keys only, firewall, automatic… Beginner · Tutorial · Linux Article Networking & firewalls · Packages & updates · Users, sudo & hardening 15 Oct 2026
• 0255 Build a monitoring stack with Prometheus, node_exporter and Grafana on one Linux server Install Prometheus and node_exporter as systemd services, scrape and query host metrics with PromQL, then add Grafana with a dashboard and an… Intermediate · Tutorial · Linux Article Prometheus & Grafana · Services & systemd 15 Oct 2026
• 0265 Turn a one-liner into a robust bash script: strict mode, options, logging, traps, locking and a schedule Grow a find-and-gzip one-liner step by step into a dependable bash script with strict mode, getopts, usage text, logging, error traps, dry-run,… Intermediate · Tutorial · Linux, macOS Article Services & systemd · Shell scripting 15 Oct 2026