A meta-data update policy in a flash memory file system

Abstract

This paper describes a new mechanism for meta-data update in file systems using flash memory. To fulfill flash memory as a stable storage system, one of its main draw-backs, meta-data update, which occupies the majority of write operations, must be reduced. That is, the file system should avoid weaknesses of flash memory, such as a limited number of program/erase cycles and its inability of in-place updates. We exploit two types of i-nodes which are allocated in separate flash areas and also introduce a delta logging method to efficiently utilise flash memory space. A trace-driven simulation shows the results that the performance of our system with two workloads is improved in terms of both time and space utilisation.