Exploring SSD endurance model based on write amplification and temperature

摘要

Write endurance of NAND Flash-based SSDs (SSD endurance for short) is essential for data reliability in storage systems. Previously, studies concentrated on different approaches to ensure SSD endurance. In this paper, we explore the SSD endurance based on write amplification and temperature. SSD endurance is determined by write endurance of NAND Flash, which depends on the limited number of P/Es in a NAND Flash. The more available P/Es a NAND Flash in an SSD has, the higher endurance an SSD characterizes. These available P/Es are influenced by write amplification and temperature. Large write amplification wears down the available number of P/Es in NAND Flash and causes data error, which degrades SSD endurance. Operating temperature influences the Fowler-Nordheim tunneling mechanism, which can cause electrons to be trapped in the tunnel insulation oxide layer of a floating gate transistor (i.e., FGT). These trapped electrons can increase the probabilities of data storage failure in a FGT. We are motivated to explore different impacts of write amplification and operating temperature on SSD endurance, and propose SSD endurance model to provide designer more useful information. By this means, new methods can be implemented to guarantee SSD endurance in storage systems.