ubuntu16.04 I reset the root password

Problem Description:

　　A user can not attach a plurality of user groups G, there is no problem in centos. Specific unclear

problem solved:

　  Reboot into startup items modifying the startup parameters set to enter the root password

reference:

https://www.cnblogs.com/xiaojianliu/p/8520313.html

01, restart the system in selected Boot boot in "Advanced optioons for ubuntu"

 02, select "recovery mode"

 03, replacing the boot into the parameters

 "recovery nomodeset" ----> "quiet splash rw init=/bin/bash"

 04, enter the password and reboot

execution proceeds to ctrl + x // init parameters after the modification is completed, and thus a series of operations set the root password!

 Is finished, you can restart! ! !