Introduction to Log-Structured File System

In the early 90s, a group at Berkeley led by Professor John Ousterhout and graduate student Mendel Rosenblum developed a new file system known as the log-structured file system“Design and Implementation of the Log-structured File System” by Mendel Rosenblum and John Ousterhout. SOSP ’91, Pacific Grove, CA, October 1991. The original SOSP paper about LFS, which has been cited by hundreds of other papers and inspired many real systems..

Observations

Their motivation to do so was based on the following observations:

• System memories are growing: As memory gets bigger, more data can be cached in memory. As more data is cached, disk traffic increasingly consists of writes, as reads are serviced by the cache. Thus, file system performance is largely determined by its write performance.

• There is a large gap between random I/O performance and sequential I/O performance: ...