Energy Characterization of Filesystems for Diskless Embedded Systems

The need for low power, small form-factor, secondary storage devices in embedded systems has led to the widespread use of flash memory. Energy consumption due to processor and flash for such devices is critical to embedded system design. In this paper, we have proposed a quantitative account of energy consumption in both processor and flash due to overhead of filesystem related system calls. A macromodel for such energy consumption is derived using linear regression analysis. The results describing filesystem energy consumption have been obtained from Linux Kernel running Journaling Flash Filesystem 2 (JFFS2) and Extended 3 (Ext3) filesystems on StrongARM processor with flash as secondary storage device. Armed with such a macromodel, a designer can choose to partition filesystem, estimate the application energy consumption (processor and flash) due to filesystem during the early stage of system design.