The Impact of File Systems on the Life Expectancy of Solid State Storage

In 1965, Gordon Moore predicted that transistor density would double every two years or so. For the most part, this observation has held true for 50 years and has become well known as “Moore’s Law.” This characteristic is a fundamental driving force behind the technological advances which have led to computers continually becoming faster, smaller, cheaper, and more reliable. Almost every aspect of technology has benefited from this characteristic – almost. Solid state memory is one area where there is a major dichotomy. Moore’s Law has resulted in smaller and cheaper storage, yet the driving need for more storage capacity has driven manufacturers to sacrifice reliability and in some cases performance.

The purpose for this paper is to discuss the characteristics of solid state memory, specifically as they relate to media life (endurance) and performance. It will discuss the challenges developers face when using solid state media in some types of embedded devices and show how alternative file systems and file system configurations can significantly improve both media life and performance in a Linux/Android environment. We present results and analysis of detailed performance tests comparing the ext4 file system with Datalight's Reliance Nitro + FlashFXe.The test environment incorporated specialized hardware to measure the exact number of erases which were internally performed on the flash media as a way of predicting the impact of file system behavior on overall media life.