Linux Help Desk Review Lab
This lesson is about fast recognition and disciplined troubleshooting. You will work through short Linux support tickets, choose the best first command, identify the likely cause, apply the safest fix, and document the result.
What this review is building
- Confidence with common Linux support tickets
- Better command selection under pressure
- Cleaner separation of symptom vs. cause
- Safer troubleshooting habits
- Short, professional ticket documentation
Help desk mindset
Good technicians do not start with random fixes. They ask: What is the first command that gives me real evidence?
That habit saves time, reduces mistakes, and makes your notes more credible.
Shift Queue
You are covering the Linux support queue. Five short tickets are waiting.
Web Service Down
User report: “The internal site stopped loading after some service changes.”
Best first command
Start with service state before guessing.
Likely clue
Service status shows failure, but not always root cause.
Best next command
Now read the logs tied to that service.
Safe fix pattern
Find the real conflict, correct it, then verify.
Check the exact error, resolve the conflict or bad config, restart the service, and confirm it is active.
No Outside Connectivity
User report: “The server is on, but it can’t reach the internet or other outside networks.”
Best first command
Confirm the adapter and IP assignment first.
Likely next check
If an IP exists, routing is the next suspect.
Common root cause
Internal address exists, but traffic has no default path.
Missing or incorrect default gateway route.
Safe fix pattern
Restore the correct route, then verify by testing gateway and external reachability.
Script Will Not Run
User report: “The backup script is there, but it says Permission denied.”
Best first command
Inspect file permissions before changing anything.
Likely clue
The file is present, but not executable.
Likely cause
No execute bit is set.
The script is readable but not executable.
Safe fix
Add only the needed permission, then test.
Disk Full Complaint
User report: “The server says there’s no space left.”
Best first command
Check filesystem usage first.
Likely next command
If one filesystem is near 100%, find what is consuming space.
Common cause
Logs, caches, or large files filled a partition.
One directory or log location grew until the filesystem filled up.
Safe fix pattern
Identify the source, clean up carefully, and verify free space after.
Do not blindly delete files. Confirm what is safe to remove, then recheck with df -h.
Hostname Does Not Resolve
User report: “I can ping an IP, but the hostname does not work.”
Best first command
Prove the difference between IP reachability and name resolution.
Likely next check
If IP works but hostname fails, inspect DNS settings.
Common cause
Name resolution is broken even though network path exists.
Missing, incorrect, or unreachable DNS server configuration.
Safe fix pattern
Correct DNS settings and re-test by hostname.
Validate network first, then correct the resolver configuration and verify hostname resolution works again.
Fast Command Map
| Problem Type | Best first command | Why it is the right first move |
|---|---|---|
| Service will not start | systemctl status service-name |
Shows current service condition before deeper log review. |
| Need service root cause | journalctl -u service-name |
Logs usually explain the actual failure. |
| No connectivity | ip addr |
Confirms whether the adapter is up and has an address. |
| Outside traffic fails | ip route |
Reveals missing or incorrect default routes. |
| Permission denied | ls -l |
Quickly exposes missing execute bits or wrong ownership. |
| Disk full | df -h |
Shows which filesystem is actually out of space. |
| Hostname fails | cat /etc/resolv.conf |
Helps verify DNS resolver configuration. |
Ticket Note Practice
Write a short shift summary covering at least three of the tickets above.
Gold-standard note:
Reviewed multiple Linux help desk tickets. For the web outage, checked service state with systemctl status and used journalctl to continue root-cause analysis. For the network issue, confirmed interface addressing with ip addr and checked routing with ip route. For the script execution issue, verified permissions with ls -l, corrected execute access, and re-tested. Also reviewed disk usage with df -h for storage concerns and verified DNS-related troubleshooting by separating IP connectivity from hostname resolution.
Micro-Quiz
Score at least 75% to unlock the next lesson.