RHEL7CentOS7 - Installation, Configuration & Management

How to secure Grub in Centos/RHEL 5/6/7 & 7.2 In this tutorial we will learn to secure Grub. GRUB or Grand Unified Bootloader, is the default boot-loader for most of the Linux distributions. It provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system’s partitions. Why do we need to secure GRUB ? When we have password protected our root or general user account, so why would we need to assign password to GRUB. We need to secure GRUB because any person with little knowledge of Linux can google “ HOW TO RESET ROOT PASSWORD  ”  & can reset the root password, if there is no password for GRUB-menu. Hence, we must secure our GRUB-menu. In Centos/RHEL, GRUB2 bootloader is used & the process to assign GRUB-password is different as in RHEL/Centos 6 which uses GRUB. NOTE:- Before we start I must warn you that you must bac...

How to reset ROOT password in RHEL7/CentOS7 Resetting ROOT password Firstly , reboot your system & when the kernel selection screen comes, press ‘e’ to edit kernel parameter Next, search for the line starting with “ linux16 ” and move to the end of that line by pressing “ end  ” key of keyboard. Type ‘ rd.break ’ without quotes at the end of the line & press “ CTRL + X ” Now, mount your filesystem in read-write mode as by default its in read-ony mode. To mount filesystem in read-write type “ mount -o remount,rw /sysroot ” & than type “ chroot /sysroo t” to make changes to filesystem Once above steps are completed , we can type “ passwd ” command & can reset our password. Now, type “ exit ” & than “ reboot ” to reboot he system. This was tutorial on resetting your password for root.