Stage 1 · Lesson 5 of 10
Packages and system logs
Software on a server comes from a . Debian and Ubuntu use apt; Fedora, RHEL and Amazon Linux use dnf. Learn to refresh the list of available packages, then install, remove and upgrade them.
Apply regularly, because an unpatched server is the easiest way in for an attacker. When something breaks, logs are the first place to look. record what services did and what went wrong. systemd collects service logs in one place called the journal.
Read one service's logs with journalctl -u nginx --since "1 hour ago", or follow new lines live with journalctl -f. Many programs also still write plain text files under /var/log. Reading logs quickly is the habit that later grows into and .
Common trapguessing at a fix before reading the error message, which is usually right there in the log.
A question to check yourself, an AI practice session and 2 cheat sheet entries come with the full roadmap. Unlock
Resources for this stage
Start with· follow one of these
- CourseFreeThe Missing Semester of Your CS Education
MIT · Beginner
Shell, scripting, data wrangling, SSH and Git in a dozen focused lectures
- BookFreeThe Linux Command Line
William Shotts · Beginner
Free book: permissions, processes, packages and longer shell scripts, chapter by chapter