Scenario: Patching run yum update using Ansible to RHEL 6/7 remote machine
System: RHEL 7, Ansible 2.6 (Callback and ansible log is active)
Remote System: RHEL 6/7 (not using ssh key), same root password.
Example yum update host group devservers, here my steps:
1) Empty ansible log.
# cat /dev/null > /var/log/ansible.log
2) Input hosts devservers in /etc/ansible/hosts
# vi /etc/ansible/hosts
[devservers] 192.168.99.18 192.168.99.19