Hmm. 15TB definitely sounds nicer than 10.... :D :D<p>I fully intend to buy disks with widely spaced apart manufacturing dates, so theoretically this should be manageable.<p>Now I get why 8 disks is recommended... you can make a mirrored pair of 4-disk raidz1s, you get &gt;50% storage efficiency, and you can lose any two disks before it dies.