At first I just wanted to see how much work it would take to port ZFS to FreeBSD. I started by making it compile on FreeBSD, and once I did that, I was quite sure it would take at least six months to have the first prototype working. The funny thing was that after another week or so, ZFS was running on my test machine
C. Danescu-Niculescu-Mizil, R. West, D. Jurafsky, J. Leskovec, and C. Potts. Proceedings of the 22nd international conference on World Wide Web, page 307--318. Republic and Canton of Geneva, Switzerland, International World Wide Web Conferences Steering Committee, (2013)