Actually I am working on checkpoint storage strategies in grid computing and I am not able to find any tool or simulator which I can use to analyze different approaches.
You should also look at SST, the structural simulation toolkit. The SST/macro tool might be useful in your work. See http://sst.sandia.gov/index.html for more info.
We used iSPD (www.dcce.ibilce.unesp.br/spd/) to simulate grid schedulers with tasks checkpointing. This simulator provides an iconic interface for modeling the grid and also the scheduler. If you are interesting in adding special features to it, please feel free to contact us.