Finding Debugging Information
When you are trying to solve problems, getting precise and specific information about the problem helps a lot. In particular, you should look for error messages.
When you find error messages, copy them down exactly. Paraphrasing usually does more harm than good. You can:
- Copy and paste the error message into a text document
- Take a screenshot of the error message
- Carefully type out the error message
Here are some ways to find troubleshooting information:
- Popup error messages in applications
- Messages that display when you run the application from the command line (if possible). Some programs have a “verbose” or “debugging” mode that can produce more output.
- Output from the commandline
dmesgcommand. This command lists bootup messages and other low-level operating system messages (such as what is detected when you plug in a USB device).
- The logfiles
- Other logfiles that may be generated by the program’
Before turning to the Internet, you might find documentation that can solve your problem installed on your computer.
Programs often contain “help” menus. These menus are often unhelpful, but sometimes they have instructions for the program, or web links to online documentation.
Installation and usage information for packages can often be found in
/usr/share/doc/. This folder contains a subfolder for every package installed on the system. Here are some things to look for:
examplesfolders, which contain configuration examples
The commandline programs
aproposcan display help pages
(called “manual pages”) for programs.
You can find help for many basic tasks in the
System -> Help andmenu.
Effective Web Searches
When looking for content on the web, you want answers that are accurate and up to date. Here are some techniques to try:
If you have a specific error message, type in that error message in quotation marks.
If you are not getting good results, include terms specific to your distribution in your search:
kernel: SCSI error : <1 0 0 0> return code = 0x70000
"kernel: SCSI error : <1 0 0 0> return code = 0x70000"
+ubuntu "kernel: SCSI error : <1 0 0 0> return code = 0x70000"
+lucid "kernel: SCSI error : <1 0 0 0> return code = 0x70000"
Refine your searches. As you find specific buzzwords, include them in your searches.
Describing Problems Effectively
You are more likely to get satisfying answers to your questions if you explain them clearly. A good problem report is succinct, but provides enough accurate detail for the reader to follow what is going on.
It can take a fair amount of time to gather information needed for a good problem report, and more time to write a report that is clear and easy to understand. The good news is that this process can clarify your thoughts — sometimes the process of writing out a question triggers an approach that solves the problem.
Here are some guidelines for writing effective problem reports.
Make your subject line informative.
- Bad: “HELP!!! I’m STUCK!!”
- Better: “My laptop fails to power down fully on shutdown”
Use good English grammar and spelling. In particular avoid “txtspeak”: “u”, “plz”, etc. Using standard English helps your readers (many of whom are non-native speakers) understand what is going on better.
Describe the hardware and software that is relevant:
- What distribution and version you are using
- If applicable, the program and version that is giving you trouble
- Relevant hardware information. In the laptop example above, you would state the make and model of your laptop.
Describe what you are trying to do.
Describe what you expect should happen.
Describe what actually happens.
Describe what steps you have tried to solve the problem. If there are common fixes to your problem listed on the Internet, you can provide URLs and state what happened when you tried them.
- http://ubuntuforums.org/showthread.php?t=1422475 : Guidelines for asking questions on the Ubuntu forums.
- http://askubuntu.com/faq : The guidelines at the Ask Ubuntu site
There are some online help forums that can be helpful.
- Be sure to learn the online culture before posting
- Be sure to search for other answers to your question before asking it
- Be sure to ask your question effectively
Here are two forums that are currently popular:
- Find a “Linux Buddy” — somebody more experienced than you who is willing to help you troubleshoot issues. (Be sure to respect this person’s time and goodwill!)
- Use local mailing lists like the kwlug-help list
- Attend some user group meetings and get to know the people there. Some of them may be willing to help (and some may not)
Use whatever means are at your disposal to find answers to the following questions. “Show your work” by documenting the steps you took to find the answers.
What command shows you disk usage information in a human-readable format?
How do you display a text file with a .gz extension?
In which file will you find the name of your computer (e.g.
What version of the Linux kernel does your computer run?
Where on the filesystem will you find common licences used in an Ubuntu system?
How many bogomips does your computer run at? (Bonus: what are bogomips?)
Complete the treasure hunt above.
Write a problem report for one problem that you have experienced with your computer recently. Use the guidelines above. We will be looking at some of these next session.
Read and evaluate at least one question (and set of answers) online. Was the question clearly stated? What could have been improved? Were the responses effective? Why or why not?
This work by KW Freeskool is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.