The fix that broke more
A technician finds that a mail setting is wrong. They change it in a hurry. Now nobody can send email at all.
There was no copy of the old setting. There was no test. And nobody wrote down what was done.
Key words
| Word | What it means |
|---|---|
| Resolution | the act of fixing the problem |
| Backup | a spare copy of data kept in case the original is lost |
| Configuration | the settings that decide how a system works |
| Fault log | a record of faults, their causes and their fixes |
| Recurrence | a fault coming back again |
| Mitigate | to make something less likely or less harmful |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can apply a fix safely, prove it works and record it so the fault does not come back.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Six steps of problem resolution
- Back up the data on the system.
- Implement the solution.
- Test the solution.
- Repeat the process until the outcome is right.
- Document the cause and the solution on the support system.
- Act so the cause cannot come back.
Why back up first
A fix is a change. Any change can go wrong. If you copy the data or the setting first, you can go back.
Back up the data on the system. For a setting, copy the file before you edit it.
A pretend broken mail setting
printf 'server=mail.college.test\nport=25\n' > mail.conf && cat mail.confA command for the lesson’s lab terminal. It is shown here and not run.
Back up the setting first
cp mail.conf mail.conf.bak && ls mail.conf*A command for the lesson’s lab terminal. It is shown here and not run.
Implement the fix
sed -i 's/port=25/port=587/' mail.conf && cat mail.confA command for the lesson’s lab terminal. It is shown here and not run.