Goals: Good consistency guarantees, snapshots and cloning (writable snapshots), decent performance.
Our first effort resulted in LinLogFS, a mostly classical log-structured FS (Freenix 2000 paper, master's thesis).
Writing an efficient cleaner that could work with snapshots turned out to be hard, so we eventually gave up on the idea of using segments and a cleaner, and reverted to a free-blocks management approach, resulting in LLFS (master's thesis, poster, talk slides (in German)). Some web pages:
Name Last modified Size Description
Parent Directory - offen.html 16-Jun-2008 11:23 3.4K poster.pdf 14-Jun-2008 15:04 1.8M poster.ps.gz 14-Jun-2008 15:09 1.8M talk.pdf 14-Jun-2008 14:59 90K