Add user to group:  useradd -G <groupname> <username> Change password:  passwd <username> Allow sudo access: visudo Server Hostname:  /etc/hosts, /etc/sysconfig/network PostgreSQL: yum install postgresql-server postgresql-cli service postgresql initdb chkconfig postgresql on /var/lib/pgsql/data/pg_hba.conf (add “host all all 127.0.0.1/32 trust” near bottom of page) service postgresql start yum commands:   remove install list <package>* list installed | Read more about CentOS cheatsheet[…]