Linux forget root password forgot what grub password

When we forget the root password if GRUB does not set a password (or know GRUB password) we can use a single user to change password, this is what we have to modify the root password using CD 1, the system CD into your CD-ROM drive, set the optical drive to boot.

2, select F2 system repair enter command: linuxrescue3, following a few select and install the system. 4 when you receive the prompt, when it should be borne in mind that his tip command: chroot/mnt/sysimage5 next step is to modify your password, we advance: chroot/mnt/sysimage disown cannot enter write mode. 6 last run command: passwd new password and confirm new password 7 restart computer. how to encrypt a grub grub: dense is divided into two, one is clear, the second is to use the MD5 algorithm for encryption. Plain text encryption: Edit grub.conf file vim/boor/grub/grub.conf in default = 0 the following plus line password = 1234567890 (this is the clear text password) MD5 encryption: have to MD5 command grub-md5-crypt calculated value, and then copy the values to the grub.conf file password--md5 $ BYxEn $ e5X/xOTS2pTpPPWtgIMhU1 (this is to use MD5 encryption value)