$ sudo groupdel foobar
groupdel: cannot remove the primary group of user 'foobar'
$ sudo usermod -g foo foobar ## Change the primary group of user "foobar" from "foobar" to "foo"
$ sudo groupdel foobar ## Done
카테고리 없음
$ sudo groupdel foobar
groupdel: cannot remove the primary group of user 'foobar'
$ sudo usermod -g foo foobar ## Change the primary group of user "foobar" from "foobar" to "foo"
$ sudo groupdel foobar ## Done