Linux Admin Commands for Developers and DBAs

Safe Linux checks for services, logs, ports and storage. Last updated August 28, 2026.

Linux administration is easier when you inspect the host in layers: identity, packages, services, logs, ports, storage and users. A DBA can use this order before opening Cockpit, tuning SQL or changing a firewall.

Host and distribution

hostnamectl
cat /etc/os-release
uname -a
date -Is
whoami
pwd

Services and logs

systemctl --failed --no-pager
systemctl status postgresql --no-pager
systemctl status mysql --no-pager
systemctl status nginx --no-pager
journalctl -p warning -n 100 --no-pager
journalctl -u postgresql -n 80 --no-pager

Ports and firewall

ss -tulpn
sudo ss -tulpn | grep -E ':(22|80|443|9090|5432|3306|1433)\b'
sudo firewall-cmd --list-all 2>/dev/null
sudo ufw status verbose 2>/dev/null

Storage and IO

df -h
df -ih
lsblk
mount | column -t
iostat -xz 1 3 2>/dev/null
du -sh /var/lib/postgresql /var/lib/mysql /var/log 2>/dev/null

Packages and updates

Package changes should follow maintenance policy. These commands identify package manager state without forcing an update.

command -v apt dnf yum zypper pacman
apt list --upgradable 2>/dev/null | head
dnf check-update 2>/dev/null | head
yum check-update 2>/dev/null | head

User and permission checks

id
groups
sudo -l
last -n 10
find /etc/sudoers.d -maxdepth 1 -type f -print

When to open Cockpit

Use Cockpit when the team needs a browser-based view of services, logs, storage or network state. Use SSH when you need exact command history, automation or a text-only emergency path.

A Linux admin check is stronger when it is timestamped. Copy the host, time and command output into the incident note before changing the server.