http://www.informatik.uni-frankfurt.de/~loizides/reiserfs/
I am undertaking a small research project investigating the effect of fragmentation on the performance of the ReiserFS file system. The project is part of my master thesis at the university of Frankfurt and is financed by the Innovative Software AG.
The objective is to find and provide a method that artificially ages a filesystem so that one gets an idea of how the performance of a given filesystem behaves under different workloads.