Here you will find a small set of testing utilities for libjio that cover
performance testing and recovery testings. They're really simple so there's
not much documentation besides the code.

Another really useful way of doing testing is using some of the well known
filesystem benchmarking applications and modify them to use libjio. I regulary
use dbench, fsx, tiobench and the tdb test suite, the patches are available on
the website.