Please read the CentOS wiki article on How To Become Root.From what you have written, it is clear ... [by AlanBartlett]
Welcome to the CentOS fora.There are a few CentOS wiki pages, which when read through, should enable you to regain control of your system. In no particular order, please s... [by AlanBartlett]
The CentOS wiki sports a page about setting up software RAID1 on CentOS
5.x. There's a section about making both members of the RAID1 bootable
by setting up GRUB on both disks.
Now I wonder how this should be done on CentOS 6.x and 7.