Seeking assistance with system faults

[Kwan Lowe]

> Message: 6
> Date: Wed, 28 Apr 2004 17:14:19 -0500
> From: "Mike Cervi" <Mike.Cervi at maryville.com>
> Subject: Seeking assistance with system faults

> Hello fellow Linux users,
>
> I am in the process of developing a Linux Trouleshooting training course.  It
> is going to be based on the Fedora and RHEL3 distributions.
>
> I am seeking help in developing faults that can be placed on student machines,
> allowing them to practice their troubleshooting skills.
>
> I am looking for "real life" situations, either hardware or software based,
> all "degrees of difficulty".  Essentially nothing is out of bounds.
> Fat-fingered files, improper configurations, incorrect permissions, etc.
>
> If you have input that you think could be helpful, I'd appreciate it if you
> would take a couple of minutes and click on the link below (to keep the
> mailing list traffic to a minimum) and fill out the form.
>
> http://www.dvl.maryville.com/feedback_agreement.asp
>
> I'll take as much input as you're willing to give... as many faults as you
> feel like passing on. I don't really think I can get "too many".
>

Mike:
 I did a Linux troubleshooting presentation at my local LUG not too long ago
and also have trained at some local technical schools. Some of the more
interesting things I did included:

1) Creating boot problems -- zapping /initrd, overwriting the superblock,
deleting the bootloader configs, overwriting grub/lilo with Winders.

2) Corrupting existing files (rot13 or just creating a similar sized file by
copying from /dev/random).  This module was for RPM usage. Specifically, I
corrupted a bunch of XFree86 files, moved some to lost+found then had the
students use the rpm auditing tools to determine what had broken and then
reinstall them.

3) Some package build problems. Mostly missing macros, missing dependencies.
This explained -devel packages, dependency tree (rpm --requires), rpmbuild,
etc.. Also showed how to patch RPMs.

4) Create network problems. Break DNS resolution, routing, etc.. Introduced
the hosts files, nsswitch, resolv.conf, etc.. Configure IPTABLES rulesets to
disallow queries, etc..

5) Fill up /var with garbage (cannot login, etc..)

6) Fill up /.

7) Break X (specifically, installed Nvidia driver then upgraded kernel; set
display resolution too high *be careful*). This introduced inittab, kernel
stuff.

8) Install bad glibc. This causes many things to break in wonderful ways.
Introduced rescue disks, rpm --root, etc..





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