This tutorial explain how to create a system administrator user after installing a CentOS 6.3 server.
Requirements
A CentOS server installed, if you didn't installed it yet have a look to the CentOS 6.x Server Installation tutorial.
Create a System Administrator user
Login as root user and create an administrator user:
centos-srv login: root
Password:
...
# useradd administrator
# passwd administrator
Changing password for user administrator.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
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Logout and login as administrator user, then try to switch to root using su command:
centos-srv login: administrator
password:
$ su -
Password:
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Make administrator user as the only a user who can switch to root by adding it to the wheel group and editing PAM service configuration:
# usermod -G wheel administrator # Add administrator to wheel group
# vi /etc/pam.d/su
...
# Uncomment the following line to require a user to be in the "wheel" group.
auth required pam_wheel.so use_uid
...
Add administrator to the sudoers file:
# visudo
...
# Add the following last lines
# System Administrator can use all root privilege
administrator ALL=(ALL) ALL
Forward emails for root to administrator user by editing the /etc/aliases file, then run newaliases command:
# vi /etc/aliases
...
# Person who should get root's mail
root: administrator
...
# newaliases
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