Accidentally forgot the root password of Linux

Many times, because the root user, we are not commonly used, so forget the password is often the case, then how can we solve it? I now know that there are two types of boot-time access to single-user mode can be directly modified root password:

Method One:

The first step:

When powered on, it enters a 3-second wait state as shown in

This time you need to quickly put the mouse into the screen (I use the virtual machine, so need to manually click into it), followed by the following state:

Step Two:

This time, press the E key to enter the grub edit state, the following interface will appear:

Step Three:

Select the second item (beginning with the kernel kernel), and press the E key to enter the editor and enter:

Fourth Step:

At the end of the manual add a single, and press ENTER enter key, will return to the third step interface, but at the end there will be one, this time by pressing the B key, will go into one-user mode, and can be successfully opened, get root login privileges

Fifth Step:

After power-on, the acquired permissions are root

Change Password with command passwd

Follow the prompts, enter the new password two times, enter the reboot restart command to

The second method:

In the first method of the first step, press the A key, and then press the space bar, in the press 1 key, you can turn on the boot, after the operation of the same, no difference