Inferring trimming activity of solid-state drives based on energy consumption

Solid-state drives (SSDs) have become pervasive in modern computing and are replacing hard disk drives in many applications. However, the mechanism by which SSDs store and modify data is intrinsically different from hard disk drives. For example, a memory location on a SSD must be erased prior to being written. The main contribution of this paper is a set of measurement and analysis techniques for inferring the behavior of a SSD by observing its power consumption. This paper measures and analyzes the energy consumption of the TRIM command for three separate SSDs. Energy and time models are derived for all three SSDs and it is shown that these models are approximately linear as a function of the size of the file being trimmed. Additionally, empirically obtained signatures are presented to identify when a TRIM command is issued to the SSD based on the observed waveform. Our findings support the hypothesis that energy and time models, as well as power signatures, differ among drive manufacturers.