Hi chaps, I recently got my FreeNAS box up and running properly, and copied over my data. Tested it out, and it seemed fine, so I decided it was as good a time as any to remove MacZFS and install OpenZFS. Before re-creating the storage pool, I decided it might be a good idea for performance to zero these drives out. I wrote a command to zero each drive out sequentially, which was ticking along just fine, at around 250MB/s. After kicking this off, I worked out it'd roughly take 12 hours to do this, and I'd prefer waking up this morning with it all done, as I'm not back at mine until Tuesday, and don't really want my machine on doing nothing for nearly a week. So I cancelled the previous command, and instead opened 4 terminal windows and via diskutil, asked it to zero out each drive at the same time. I checked the throughput with Activity Monitor and disk writes shot up to 750-950MB/s, and left it at that. This morning I checked on its progress. 1 drive was 80% finished. 2 were 50%, 1 was only 10%. Since each one individually would only taken a couple of hours or so, this was a bit confusing I checked disk writes. 5-10KB/s. Oh. Restarted the Mac Pro, and couldn't log in. Restarted it again and it wouldn't finish booting. Removed all drives, and put another drive in Bay 1. Disk Utility and System Information couldn't see a drive. Put the original disk from Bay 1 to my eSATA adapter. The disk spun up, and OS X crashed. It looks like I've not only managed to screw the drives up, but also the SATA-II ports on the logic board. Anyone able to confirm if this would be expected behavior, or if that kind of thing shouldn't happen?