Traditional storage systems, such as NAS, SAN, are largely unaware of the users and applications actually using the storage, because block-based storage devices manage opaque data blocks. But, with OBSS (object-based storage system), the attributes and methods among the storage devices can be adopted in the storage system, the data can be distributed on some of the storage devices and organized better to anticipate users demand. In this paper, the scalability of object storage (including object attributes, object methods and OBSS) is studied. And a self-managing approach, denoted adaptive policy trigger mechanism (APTM), is presented. APTM borrows proven machine learning techniques and takes the perspective scalable object storage. The implementation reveals that APTM is the embodiment of the idea about smart storage device and facilitates to self-manage mass storage system.