Last week i upgraded from 14.04 to 16.04 but it failed along the way that i cannot reach the desktop, but i am able to enter the terminal(but without apt-get & purge commands) i tried dpkg --configure -a. but it still failed to do so. the cause of the failure was because of mysql-server-5.7. So, after lot of booting from previous kernel, ubuntu suddenly it was fixed. i can't recall what i did or how did it happen.
So, my question is how to check the system if everything was properly fixed? What command should i use?