Restart the instructor machine. It probably means that the students are connecting to the previous instructor who forgot to logout.
It means there are some dot files that need to be updated. Remove the .mozilla and .cache directory using the following commands
cd To change to the home directory rm -r .mozilla To remove the .mozilla directory rm -r .cache To remove the .cache directory
You can check quota usage with:
quota -v First number shows used amount, second number shows allowed amount du -sk * .??* Shows directory or file with a high number. Use again inside directories.
Files to remove (using rm) are:
If you are going to drag the files into the trash, please also empty the trash!