How to free HDD space

I had difficult to access on my desktop on Ubuntu 19.10.

• As first step I rebooted the system and accessed Ubuntu in a safe modality and, later, I chose the option to start a terminal in root mode
• on the device sda8 (/) the space was over (I used df -h):
  
  
  

  In this picture /dev/sda8 has a sufficient space to allow me to start the OS

• I noticed that time ago I had problem with my notebook camera that didn't work properly
• then I tried to know how much was the size of the files in /var/log folder to know if something interesting could have come out and I found just that file, related with my camera, was larger in size than it normally could have been, even more then 6 Gigabytes!!



the offending file was called uvcdynctrl-udev.log (in the red rectangle above). In the picture it doesn't have a large size (because I proceeded to delete it).


• I proceeded to delete it (don't panic! It will be recreated again by the system)
• Then I was able to start again my Ubuntu 19.10

P.S. if you want to try another way to show the space occupied by some file or folder I suggest you to install ncdu:

 

Hacking party!!

Yep, the title could be misleading, but for it means that I found a solution for many of my comoputer problem in one night!

Here are some of them:

Problem 1: finding file usber.sys 

This file is more important if you were in my situation, that is, connecting an Arduino UNO Rev.3 on an old notebook Acer Aspire 1690 (with Windows XP mounted) that didn't recognise the usb peripheral on which was connected arduino.

After a long search I found a good man who shared the file he found on the forum at the following address:

• http://forum.arduino.cc/index.php?topic=98697.15

Thanks r0oland, thanks a lot! (Everyone can find that file at that forum address).

Problem 2: sharing my wifi connection from an Ubuntu os through an Ethernet LAN towards a Windows XP os notebook.

In this case I simple googled the solution and I found it at this address (in italian):

• https://www.lffl.org/2013/08/ubuntu-condividere-facilmente-la.html

Thanks to roberto.ferramosca.

Problem 3
In this way I was able to solve my third and final problem, namely to make my arduino work and continue to experiment and collect data on air pollution and more.

In conlusion:

SHARING SOLUTIONS MAKES THIS WORLD A BETTER PLACE!!