CentOS Daily

1. Another app is currently holding the yum lock

ps ax | grep yum
sudo kill -9 pid

1. Change the hostname of the server

# hostnamectl status
# hostnamectl set-hostname Your-New-Host-Name-Here
# hostnamectl set-hostname "Your New Host Name Here" --pretty
# hostnamectl set-hostname Your-New-Host-Name-Here --static
# hostnamectl set-hostname Your-New-Host-Name-Here --transient

1. firewalld configuration