TroubleShooting

My program does not start

If your program does not start

• make sure you have execute priviledges for it using the command

ls -l

• make sure the program can load its libraries using the command

ldd

• look what the problem is using the command

strace

Cannot do graphics

Warning: No xauth data; using fake authentication data for X11 forwarding.

=> have you changed your hostname?

My network connection is broken

• TroubleShooting network

Umount does not work

lsof | grep /mnt

Then kill the process.

root-Password is lost

Boot Linux with the parameter "init=/bin/bash" You get a root-shell. Enter:

mount -o remount, rw /
passwd
mount -o remount,ro /

and reboot

find out which files are accessed by a program

To find out which files are accessed by a program start it with

strace -e open program

Scripting

Use xtrace to get every line of a script shown before the line is executed.

If you want every line to be shown with evaluated values, write the following to the beginning of the script:

set -x

or -xv for verbose