vagrant init centos/7
vagrant up --provider virtualbox
vagrant box add centos/7 # for CentOS Linux 7
seq 1 6 |xargs -L 1 -I {} -t vagrant up "node-0{}"
seq 1 6 |xargs -L 1 -I {} echo "192.168.15.15{} node-0{}"
vagrant plugin install vagrant-persistent-storage
vagrant global-status
vagrant global-status --prune