Zerethon IDE
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Linux servers and SSH

Beginner 12 min read

Connect to a server securely, find your way around and keep it updated.

Why it matters

Most applications end up on a Linux machine — a VM, a container host or a managed server. Being able to sign in, read a log and restart a service is the difference between fixing an outage and waiting for someone who can.

Where it fits

  1. Plan & Design
  2. Develop
  3. Version control
  4. Verify
  5. Build & Package
  6. CI/CD
  7. ● Deploy › Servers & containers
  8. Operate

What you will learn

  • Sign in with an SSH key instead of a password.
  • Inspect services, logs, disk and memory.
  • Apply security updates.

Before you start

Sign in with a key

Example 
ssh-keygen -t ed25519 -C "you@example.com"   # once, on your computer
ssh-copy-id deploy@203.0.113.10               # put the public key on the server
ssh deploy@203.0.113.10

Look around

Example 
systemctl status nginx         # is the service running?
journalctl -u nginx --since "10 min ago"
df -h                          # disk space
free -h                        # memory
sudo apt update && sudo apt upgrade   # Ubuntu/Debian updates

Watch out: Turn off password sign-in for SSH once keys work, and never share a private key. Each person gets their own key so access can be removed individually.

Tip: A full disk is behind many mysterious outages (databases and logs stop writing). Check df -h early.

Official documentation and references

Documentation

Guides

Reference

Learn next

Related topics

Done with this topic?

Reviewed 2026-10-23. Links go to the official documentation unless marked otherwise.