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Troubleshooting In Linux!

This document was created by the North GA LUG Group.


If your system or an app locks up it can be a frustrating experience. Here are some tips and tricks to get you back on your feet.

Process Monitoring

General Tips

Checking Hardware

Black Screen w/ blinking cursor

Especially Nvidia users
- Hit ‘e’ at the GRUB screen to edit the settings
- add ‘nomodeset’ before ‘quiet splash’ in the entry
- What does this do? Instructs the kernel to not load video drivers and use BIOS modes instead until X is loaded.

Can’t Boot

Checking Logs

$ less /var/log/messages (System logs)
$`dmesg | less`  (Kernel logs)
  $ `journalctl -b` (-b switch shows all messages since last reboot)
  $ `journalctl -b -p err` (shows messages marked as an error)
$  grep EE /var/log/Xorg.0.log 

*Note some distros utilize a different general log. Some Debian based distros uses /var/log/syslog vs. /var/log/messages as it’s main log. If you don’t have messages just change the end of the command to syslog in place of any of the commands above or below.

Searching Keywords In Logs

Monitoring Logs

As an example:

For openSUSE, Rhel you can use:

sudo tail -f -n 6 /var/log/messages

For Debian based distros

sudo tail -f -n 6 /var/log/syslog

The ‘f’ switch tells it to follow
The ‘n’ switch tells it to display last N’th number of lines

Network Troubleshooting

Backup Solutions