Gfilui

My machine was in 14.04 with gnome fallback
I ve started the update towards 16.04, went ok.
Now when I log in the icons are just enormous"

If I log in with guest session, it goes on Unity with correct size.

Someone knows files to erase or modify to fix that?

You can try to open unity-control-center, then select Displays in it and set other screen Resolution (preferable native for your monitor):

• 
  

  from terminal with

  
  
  

  unity-control-center display
  

  
  



• from GUI by clicking on Gear in top right, select System settings and then Displays (you can move window by clicking Alt+F7).



• 
  

  or programmatically (change '1920x1080+0+0' below to your resolution, second part resets scaling which may be the problem too)

  
  
  

  sudo apt-get install dconf-cli
  
  dconf write /org/compiz/profiles/unity/plugins/core/outputs "['1920x1080+0+0']"
  
  dconf write /org/gnome/desktop/interface/scaling-factor 'uint32 0'
  dconf write /org/gnome/desktop/interface/cursor-size 24
  dconf write /org/gnome/desktop/interface/text-scaling-factor 1.0
  dconf write /org/compiz/profiles/unity/plugins/unityshell/icon-size 48
  

  
  
  

  if above does not help try XRandr - xrandr -s 1920x1080.

  
  

If you do not have personal settings of Unity and/or GNOME you may want to backup

dconf dump / > dconf_backup

and then reset them with:

dconf reset -f /org/compiz/
dconf reset -f /org/gnome/
dconf reset -f /com/ubuntu/user-interface/

also try

unity --reset

For Ubuntu 17 the following works

1. Open nautilus app


2. Right corner select view 'grid icon'


3. Use mouse scroll to adjust thumbnail size


4. Now go to desktop see the changes.