🛡️ System Administration

Ansible Active Directory with SSSD Troubleshooting Active Directory authd Ubuntu Login with Microsoft Entra ID Samba Postfix Creating SSH Keys Passwordless SSH Login Creating TLS Certificates OpenSSL Systemctl IP Command nmtui Set Up the Network from a Text Menu NIC Bonding firewalld Zones, Services and Rich Rules iptables Rules, NAT and Safe Changes nftables Tables, Sets and Rulesets ufw The Uncomplicated Firewall SELinux Labels, Denials and Fixes Dig BIND Run Your Own DNS Server Nmap Tcpdump tcpdump Filters the BPF Language Wireshark Htop Ps Lsof Recover a Deleted File superfile A Terminal File Manager Iftop Strace Ltrace Perf Nagios Core Hosts, Services and Alerts Checkmk Monitoring with Auto-Discovery Zabbix Install, Hosts, Triggers and Alerts Prometheus Metrics, PromQL and Alerting Grafana Dashboards, Data Sources and Alerts Loki Log Aggregation, LogQL and Alerts MySQL MySQL Replication PostgreSQL Receive-Only Mail in Docker SSHFS Remote Folders over SSH systemd Units and Timers Disks, LVM and Filesystems Users, Groups and sudo Package Management Across Distros Ansible One-Liners Ansible Roles and Projects Ansible Semaphore A Web UI and API for Playbooks Puppet Chef Salt Network Troubleshooting Nginx Guide journalctl The systemd Journal rsync Copy, Mirror and Back Up ss Sockets and Listening Ports cron Scheduling Jobs Runbook Slow Server / High Load Runbook Disk Full Runbook Server Won't Boot Runbook apt update Fails on i386 Air-Gapped Repositories for Ubuntu and Red Hat TLS Certificate Monitoring