Reset root Password

Reset root Password 2016/01/31

	If you forgot root Password, it's possible to reset it like follows.
[1]	Restart System and when GRUB2 boot menu is displayed, Push "e" key.  Next, Proceed like follows to reset root password.

# push "e" key CentOS Linux (3.10.0-327.4.4.el7.x86_64) 7 (Core) with debugging CentOS Linux (3.10.0-327.4.4.el7.x86_64) 7 (Core) CentOS Linux (3.10.0-327.3.1.el7.x86_64) 7 (Core) with debugging CentOS Linux (3.10.0-327.3.1.el7.x86_64) 7 (Core) CentOS Linux 7 (Core), with Linux 3.10.0-229.el7.x86_64 CentOS Linux 7 (Core), with Linux 0-rescue-ffa496be96ad482cb94373394cec7 Use the ^ and v keys to change the selection. Press 'e' to edit the selected item, or 'c' for a command prompt. setparams 'CentOS Linux (3.10.0-327.4.4.el7.x86_64) 7 (Core)' 'fedora' load_video set gfxpayload=keep insmod gzio insmod part_msdos insmod xfs set root='hd0,msdos1' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint='hd0,msdos1' c4df086e-3699-4e02-b7cf-b47e614f6920 else search --no-floppy --fs-uuid --set=root c4df086e-3699-4e02-b7cf-b47e614f6920 fi # add "rw init=/bin/bash" to the end of line # remove "rhgb", "quiet", "LANG=***" all if there are in this line linux16 /vmlinuz-3.10.0-327.4.4.el7.x86_64 root=/dev/mapper/centos-root \ ro rd.lvm.lv=centos/root rd.lvm.lv=centos/swap console=ttyS0,115200n8 systemd.debug rw init=/bin/bash initrd16 /initramfs-3.10.0-327.4.4.el7.x86_64.img Press Ctrl-x to start, Ctrl-c for a command prompt or Escape to discard edits and return to the menu. Pressing Tab lists possible completions. # after inputting above, push "Ctrl-x" key to proceed ..... ..... [ OK ] Stopped udev Coldplug all Devices. Stopping udev Coldplug all Devices... [ OK ] Started Plymouth switch root service. [ 6.814528] systemd-journald[95]: Received SIGTERM from PID 1 (systemd). bash-4.2# # after initramfs switch_root prompt is displayed, do like follows # set SELinux relabeling on next boot if you enabling SELinux bash-4.2#  touch /.autorelabel # set password bash-4.2#  passwd  Changing password for user root. New password: Retype new password: passwd: all authentication tokens updated successfully. # restart System and complete to reset bash-4.2#  exec /sbin/init