A few people are continuing the concept to other tools -- that should be available at http://fileutils.io/ relatively soon.
We also had another tool written on top of https://github.com/hpc/libcircle that would gather metadata on a few hundred-million files in a few hours (we had to limit the speed so it wouldn't take down the filesystem). For a slimmed down version of that tool, take a look at https://github.com/hpc/libdftw
https://github.com/hpc/dcp
We got an IEEE paper out of it:
http://conferences.computer.org/sc/2012/papers/1000a015.pdf
A few people are continuing the concept to other tools -- that should be available at http://fileutils.io/ relatively soon.
We also had another tool written on top of https://github.com/hpc/libcircle that would gather metadata on a few hundred-million files in a few hours (we had to limit the speed so it wouldn't take down the filesystem). For a slimmed down version of that tool, take a look at https://github.com/hpc/libdftw