Do artigo:
chmod g+s <directory> //set gid
setfacl -d -m g::rwx /<directory> //set group to rwx default
setfacl -d -m o::rx /<directory> //set other
Em seguida, podemos verificar:
getfacl /<directory>
Saída:
file: ../<directory>/
owner: <user>
group: media
flags: -s-
user::rwx
group::rwx
other::r-x
default:user::rwx
default:group::rwx
default:other::r-x
Mais informações: link