Solution found, I want 770 for user+groupvideo

a)create the zfs volume

zfs create proof1 

b)very important otherwise don't work!

zfs set aclinherit=passthrough rpool/proof1 

c)now the acl

chmod g+s /proof1 chgrp video /proof1 chmod A=owner@:full_set:fd:allow,group:video:full_set:fd:allow,everyone@:full_set:fd:deny proof1 

fd mean file and dir inherit

d)I create the files... and dir

mkdir dir1 touch file1 drwxrws---+ 2 root video 2 23 feb 02.59 dir1 -rwxrwx---+ 1 root video 0 23 feb 02.59 file1 

Perfect.

Solution found, I want 770 for user+groupvideo

a)create the zfs volume

zfs create proof1 

b)very important otherwise don't work!

zfs set aclinherit=passthrough rpool/proof1 

c)now the acl

chmod g+s /proof1 chgrp video /proof1   #this if you don't share the dir via nfs chmod A=owner@:full_set:fd:allow,group:video:full_set:fd:allow,everyone@:full_set:fd:deny /proof1 #this if you want to share it via nfs chmod A=owner@:full_set:fd:allow,group:video:full_set:fd:allow,everyone@:read_set:allow /proof1 

fd mean file and dir inherit

d)I create the files... and dir

mkdir dir1 touch file1 drwxrws---+ 2 root video 2 23 feb 02.59 dir1 -rwxrwx---+ 1 root video 0 23 feb 02.59 file1 

Perfect. I test it via local file, and only users which belong to video group can write on dir.