Linux doesn't produce unwanted junk files, but after upgrading, Linux will not automatically delete those files.
Clean Cache
$ sudo apt-get autoclean # Clean old version application's cache $ sudo apt-get clean # Clean all application's cache $ sudo apt-get autoremove # Remove the isolated software systems no longer in use
Cleaning up isolated software packages:
$ sudo apt-get install deborphan -y
Clean Kernel
Check current kernel:
$ uname -a
Check all kernel:
$ dpkg --get-selections | grep linux
Remove useless kernel:
$ sudo apt-get remove linux-image-x.x.xx-xx-generic $ sudo apt-get remove linux-headers-x.x.xx-xx $ sudo apt-get remove linux-headers-x.x.xx-xx-generic