OWC Thunderbay 4 with Mac hardware on FreeBSD 10.1

[Joel Lopes Da Silva]

Hi everyone,

I just bought an OWC Thunderbay 4 enclosure (external 4-bay storage enclosure with dual Thunderbolt 2 connectivity), that I would like to use on a Mac running FreeBSD 10.1. I bought the enclosure without any drives, and only installed two brand new WD Red 6TB drives (leaving the other 2 bays empty for now).

So far, FreeBSD seems to have trouble finding those drives, and I'd like some help to find what I may be missing to allow FreeBSD to use those drives. So here are some more details on what I tried.

First, to verify that the hardware was in working condition, I plugged it to my Mac with OS X Yosemite running. Obviously, OS X recognized the two independent drives, and suggested that I "initialize" them (which is OS X speak for creating a partition table and a file system). Since I'd like to use those drives for a ZFS setup, I simply declined, and left them as is.

Then I dd'd FreeBSD-10.1-RC3-amd64-memstick.img into an external USB drive, and tried to boot my Mac from that USB drive without the enclosure connected at first. Everything worked well, and after I picked "Live CD", camcontrol devlist showed 3 little devices. Then I halted the machine, plugged the enclosure back on the Thunderbolt port, and tried booting from that USB drive again; for some reason, I could never get into the boot loader menu, I was just stuck with a totally black screen and a blinking cursor. All the while, I could hear the drives in the enclosure seeking periodically, as though the boot loader was looking for valid file systems in the drives. I waited there about a full minute, with no visible signs of progress.

Then I thought I could workaround the problem by waiting until after the boot loader menu was presented to plug the enclosure; my thinking is: that is still before we actually load the FreeBSD kernel, so presumably, the enclosure would be connected well in time for the kernel to find them. When I tried that, I could successfully get into the live CD, but camcontrol devlist still didn't show the drives. Maybe this test was fundamentally flawed because I might need to let the Mac firmware initialize the connection to the Thunderbolt enclosure before doing anything, but I don't know.


I'm a bit at a loss to understand what's missing here. So many different things could be at fault that I'd like some pointers as to which direction to dig into. Here are the various things I can think of:

1. Maybe FreeBSD 10.1 doesn't have the right driver to use Thunderbolt storage peripherals on this Mac.
2. Maybe it doesn't have the right driver to talk to WD Red 6TB drives.
3. Maybe it doesn't have the right driver to talk to this specific Thunderbolt enclosure, the OWC Thunderbay 4.

#2 seems quite unlikely to me, those are probably pretty standard drives after all.
#1 seems also a bit unlikely, given that I've had good success using another Thunderbolt enclosure, the Promise Pegasus J4, with FreeBSD 9 on another Mac.

So the most likely explanation to me is possibly #3.

But then again, I'm mostly speculating. Can you guys help me find some debugging data with the right commands so I'd be able to get some more tangible information as to what I'm missing to be able to use this setup?

Thank you very much in advance for your help.