UFS MHDDFS

I am building a new system which will be more powerful then my last. My issues is that I'm using MHDDFS and I have 1 drive that is failing. I know i can just plug the drives in and reset it up and I should be good. The problem is I don't want to do that. I want to remove the failing drive of the data it stores. Then I want to make a few Raids with the drives and then add those back into the MHDDFS and get it up and running.. How can I find what files are sitting on that drive