Run grep denied /var/log/auth.log.
grep denied /var/log/auth.log
Lesson 183 of 360
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Troubleshooting · 8 minutes
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learner@clairos:/home/learner $
Unix ops lab: type a command, press Enter
Instructions
8 minutes
Click any instruction for the command details, the why, and the common mistake to avoid.
Run journalctl -u ssh | grep refused.
journalctl -u ssh | grep refused
Run grep warn /var/log/nginx-error.log.
grep warn /var/log/nginx-error.log
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Lesson support
What to notice while you play.
Search multiple logs for related clues.
Run the commands in order and compare the outputs.
Junior operators build confidence by gathering evidence before changing systems.
- Skipping the inspection step.
- Assuming one command tells the whole story.
Reference
Commands in this lesson.
grep [-i] <text> <file>
Find literal text inside a file.
journalctl -u <service>
Read simulated service journal entries.