[StuCo 98008]
GNU/Linux for Beginners

Session 6

The Art of Troubleshooting

By the end of this lecture you will know

How to get more information about an application

How to use the UNIX manual pages

How to find solutions on the Web

How to ask for help in mailing lists

Find the solution online

Search engines: query web pages and USENET archives.

http://www.google.com (web + groups)

http://marc.theaimsgroup.com

Special GNU/Linux help websites

http://tldp.org - The Linux Documentation Project

http://justlinux.com/nhf

http://www.mandrakeuser.org/docs/index.html

http://www.linuxquestions.org/questions/index.php

Learn more about your application

Application homepage

FAQ section

Mailing lists section

Documentation installed on your machine

/usr/share/doc

Comments in configuration files

Manual pages (man)

Help on Command-Line Tools

Manual pages

$ man “java”

Search for strings with / (same with less, vi)

$ apropos “java” (all relevant man pages)

Info pages

$ info emacs (CTRL-X CTRL-C to get out)

“info:” in Konqueror address bar (simpler to use)

$ whatis df

Mailing Lists

Resist the temptation – never send a personal email

Goes double for developers

Goes quadruple for Linus himself (!)

Know the code of conduct of each mailing list (netiquette)

General rules

Be polite, they're doing you a favor anyway

Be precise, they can't read minds

Try to solve your problem before asking for help

Send [SOLVED] and thank people who help you

Style Crimes

http://www.catb.org/~esr/faqs/smart-questions.html

“Linux SUCKS!”

“I NEED HELP FAST QUICK AND PRONTO”

“My computer doesn't work! Help!”

Top-posting

HTML email

Quoting 5,000 lines to add a “Yeah, me too”.

Replying to an irrelevant thread.

Ditto, but changing the Subject field.

How to figure out what's wrong

Is it a GUI application?

Run it from the command line

Is it a daemon/server?

Check system logs like /var/log/messages

# grep -n “dsl” *.log

What is the application doing?

$ strace <application name>

$ lsof | grep “application name”

$ ps auxf (look for parents/children)

$ top -c

Google newsgroups search is currently the most promising search. Try searching for the exact error message you're getting, or describe what you're trying to do. Try the same query on WWW and on newsgroups.

MARC (Mailing list ARChives) is a nice searchable repository of mailing lists that pertain to many GNU/Linux topics.

Configuration files for servers and daemons (like sendmail, cron, apache, privoxy etc) are usually so well commented, that more than 80% of the configuration file is taken up by comments, explaining how you should use the remaining 20%!

Manual pages are invoked with the $man command.

$ man ls

gives the manual page of “ls”. There are different sections of manual pages, depending on what kind of perspective you have.

Try:

$ man 2 reboot

$ man 8 reboot

If you can't find the proper mailing list, try locating a LUG (Linux Users Group) and searching their mailing list archive.

An example of a LUG close to CMU is WPLUG (Western Pennsylvania Linux Users Group).

Sometimes, the mailing list archives do not have a search interface on the web – you need to download the archive and search it manually. That's fine, just grab the tarball, extract it, and use less to read through it and look for strings of interest, or just grep -n through it.

Not knowing HOW to ask, guarantees you won't get the answer you're looking for. Have in mind that some of the people lurking on mailing lists have been there for years, answering the same questions over and over and over again. Search the archives of a list BEFORE asking for something, as some consider it a waste of time answering to a question that has already been answered (and thus archived) the previous week.

Session 6 - The Art of Troubleshooting

[StuCo 98008] Introduction to GNU/Linux

gnu linux troubleshooting mailing list usenet newsgroup google search engine man apropos help newbie netiquette

As users of GNU/Linux systems, you have a wealth of resources available to you in case you don't know how to do something, or how to resolve an issue.
+ Websites dedicated to helping new users
+ Web search engines
+ USENET and mailing list archives search engines
+ Documentation installed with the application in question
+ man pages
+ online help with the --help switch
+ apropos (search manual pages)

2003-09-11T14:09:36