System administration for Linux servers. Manage packages, services, and system configuration. Use when administering Linux systems.

Linux Administration Core Linux system administration skills for managing production servers, development environments, and infrastructure hosts across Debian/Ubuntu and RHEL/CentOS distributions. When to Use Provisioning and maintaining Linux servers in any environment Installing, updating, or removing software packages Managing filesystems, disk usage, and mount points Investigating runaway processes or high resource consumption Scheduling recurring tasks with cron or systemd timers Analyzing system and application logs for troubleshooting Prerequisites Root or sudo access on the target system SSH access configured (see ssh configuration skill) Familiarity with a terminal text editor (vim, nano) Package manager available ( apt on Debian/Ubuntu, dnf on RHEL 8+/Fedora) Package Management Debian / Ubuntu (apt) RHEL / CentOS / Fedora (dnf) System Information Filesystem Management Process Management Cron Job Management Log Management Networking Essentials Troubleshooting Symptom Diagnostic Command Common Fix Disk full df h and du sh /var/log/ Clear old logs, run logrotate f , remove temp files Out of inodes df i Delete many small files, check /tmp and mail spools High CPU usage top , ps aux sort= %cpu Identify and restart or kill the offending process High memory / swapping free h , vmstat 1 Tune vm.swappiness , add RAM, identify memory leak Service won't start systemctl status <svc , journalctl u <svc Check config syntax, file permissions, port conflicts DNS resolution fails dig @8.8.8.8 example.com , cat /etc/resolv.conf Fix nameserver entries, restart systemd resolved Package dependency error apt fix broken install or dnf distro sync Resolve held or conflicting packages SSH connection refused ss tlnp \ grep 22 , systemctl status sshd Ensure sshd is running and firewall allows port 22 Related Skills ssh configuration Secure remote access to Linux servers user management Create and manage users, groups, and sudo systemd services Write and manage systemd unit files performance tuning Kernel and application performance optimization backup recovery Protect server data with automated backups

linux-administration