A Filesystem for Lots Of Little Files (LOL FS) Allison Regier and Karen Hollingsworth University of Notre Dame

Both of us use many small files in our research projects. The Problem y1 x1 r1 y2 x2 r2 24 byte files composed of approximately 24 ascii characters: Files that are 200 to 1000 bytes each, of ascii text: AAGTCACTCG…

Lots of little files require lots of overhead space and time! The Problem Amount of Data Total Disk Space Used Time Single File1,000,000 Bytes = 977 KB 984 KB< 1 second 100,000 Small Files 1,000,000 Bytes = 977 KB 394 MB1106 seconds

We use a single large file behind-the-scenes for many small files of data. The Solution Name size flags filedata Name size flags filedata Name … variable Number of bytes for each field

 Assumes files will be written once and not modified  Achieves excellent space performance!  Needs improvements in time performance Characteristics our file system The Solution

Writing 10,000 files, 10 bytes each Initial Results TimeSpace Linux seconds kilobytes LOL FS seconds 348 kilobytes

The Road Ahead  Improve the time performance of our filesystem  Fix memory errors that occur during large-scale testing  Perform more tests to compare our filesystem to a traditional file system Future Work