So my iMac Pro has been crashing on shutdown. I shutdown and the computer seems to fully shut down, but then restarts and shows a crash. The crash kept showing com.apple.iokit.IOStorageFamily as the crash, so I realized it was hard drive related.

Now I have a lot of hard drives hooked up to my computer, not only for work, but for personal use as well, and I currently have 2 OWC Thunderbays hooked up to my mac, one Thunderbolt 3 which is mine and a Thunderbolt 2 that is works, and about 3 work hard drives, plus 4 external hard drives for storage in one 4 bay from OWC as well as s couple other storage and backup drives, and an external SSD as a media cache and about 4 work hard drives, and the internal on my iMac Pro. So a metric shit ton of hard drives.

Now I started disconnecting drives and trying things and got various results, with the problem occurring with different drives, but then finally it came down to the second OWC Thunderbay, the Thunderbolt 2 one. And if I turn that off the problem stopped happening. So I started wondering if it was the 2 different drives, and I wrote to OWC / Softraid as they are both OWC drives with softraid.

I gave them the crash report, and they told me something I didn’t know.

This is a kernel bug in MacOS. To avoid this, unmount and disconnect the USB drives before shutdown. (or your thunder bay). Its a known bug that 12 drives will cause a Mac to crash at shutdown.

Well how long has Apple had this damn issue. I know most people don’t get close to that, but I have surpassed it and ran the fuck into it.

Sure I can shut drives down first, but that is certainly a pain in the ass. And sometimes I have to shutdown the drives, then restart and then I can shutdown.

Color me frustrated, but OWC was fast and helpful.