http://case-of-t.net/2013/01/07/samba-4os-requirements/
http://wiki.gentoo.org/wiki/Centralized_authentication_with_Samba_AD_/HOWTO
http://d.hatena.ne.jp/torutk/20130301/p1
http://wiki.gentoo.org/wiki/Samba4_Migrating/HOWTO