The mental checklist I use when troubleshooting Linux servers

Source: Dev.to

Step 1: What is broken?

• Service not running?
• Server unreachable?
• Performance issue?
• Permission issue?
• Always define failure first

Step 2: Is the system alive?

• Can I SSH in?
• Is the server responsive?
• Is the disk full?
• Is RAM exhausted?

Step 3: Is the service running?

• Is the process running?
• Did it fail to start?
• Did it crash?
• This eliminates 50 % of issues

Step 4: Check logs

• Why it failed
• What it tried to do
• What it couldn’t access
• Learn to scan logs, not read every line

Step 5: What changed last?

• Updates
• Config edits
• Permission changes
• New files
• Always ask: what changed?

Step 6: Narrow scope

• Is it one user or all users?
• One service or the whole system?
• One port or all networking?
• This prevents panic

Step 7: Test ONE thing at a time

• Make a small change
• Restart service
• Observe
• Never shotgun‑fix

Step 8: Confirm + document

• Is it fixed?
• Why?
• What would I do faster next time?
• That’s real troubleshooting