The present invention provides \u03b2-hydroxy phosphonate compounds that are autotaxin inhibitors. In this regard, in one embodiment, a method is introduced comprising allocating a temporary file that occupies free space on a flash memory, determining specific blocks of the flash memory that the temporary file occupies, generating TRIM commands for the specific blocks, and deleting the temporary file. The rotor assembly is rotating inside or outside of circular or non-circular stator depending on the configuration chosen.