Linux skips password methods and prevents others from skipping passwords

Linux Root is Superuser, once the root password is forgotten or stolen, is a very headache, there will be a great danger so how to get back the root password?

Summarized as follows:

(a) Linux system password cracking

1. In Grub Option Menu Press E to enter edit mode

2. (press e) Edit kernel line add/init 1 (or/single)

3. Press B to restart

4. After entering execute the following command #vi/etc/passwd into the passwd file will be the first line of root:x:0 .... In the x Delete, become root::0 .... Then save the exit! In the system, the root password is empty at this time.

Change Password #passwd root

How to prevent being skipped by others?

Skipping passwords is generally used in single-user mode to enter the system, you can set a password to grub, so that no grub password can not enter the single-user mode.
Vi/boot/grub/grub.conf
Add a line to the title and password=***** is OK.

Linux skips password methods and prevents others from skipping passwords