Love ZFS, hate having to use it in FreeBSD or Illumos, so I like seeing someone successfully using it in Linux even if licensing concerns keep me from doing it. When I saw that he was using "WD Caviar Green" hard drives, though, I cringed.

These "green" hard drives tend to be very aggressive about parking heads and spinning down the platters. While this is fine if a disk is going to sit idle for a long period of time, in cases like an OS partition and memory buffering, these drives start destroying themselves spinning down and cranking up several times a minute.

We had 4 out of 16 fail one week after burn-in in a raidz configuration. We had plenty of hot spares for various reasons of paranoia, and they didn't go all at once, so we recovered and replaced the entire batch with Constellations.

The only positive note was that we are now firmly in love with zpools and zfs.. It made egregious hardware failure a manageable problem.