to reset vi-admin password, check that.
1- At the GRUB splash screen at boot time, press any key to enter the GRUB interactive menu.
2- Select Red Hat Enterprise Linux with the version of the kernel that you wish to boot and type a to append the line.
3- Go to the end of the line and type single as a separate word (press the Spacebar and then typesingle). Press Enter to exit edit mode.
4- When Start promp type: passwd vi-admin
:smileywink: Enjoy