I see some of the same questions come across a variety of mailing lists. Often times the questions are phrased differently, but they are essentially asking the same things over and over again. This is not a bad thing as new people are introduced to ZFS and start asking about it. I find that I am sending people to a number of links where people who know more about ZFS than I have already answered the questions. To simplify giving out all these URLs I am gathering them up here for reference in one place. Expect this list to grow as I find more good write-ups on ZFS and ZFS related topics.
These will all open in a new tab or window.
Richard Elling on MTTDL and ZFS configurations MTTDL == Mean Time To Data Loss or a relative measure of how safe your data will be
My ZFS Resilver Observations from replacing a drive in 2014
My ZFS Performance vs ZPOOL Layout results from testing I did while at a client in 2010
FreeBSD Wiki ZFS Tuning Guide FreeBSD specific, slightly dated, has some recommendations but does not fully explain them