ACL

# Mount with acl support
/dev/mapper/root   /    ext3    errors=remount-ro,acl   0  1
# Remount
mount -oremount /
# Use this to set default act (Lookup groups to set default group)
setfacl -dm u::rwx,g::rwx,o::r /shared/directory
 
# Add a group permission (to execute)
setfacl -m group:mysql:x /home/mysql
# Remove group permission
setfacl -x group:mysql /home/mysql
# Remove all acls
setfacl -b /home/mysql