Annoyingly, disk discovery. It refused to use my disks, claiming they didn’t have serial numbers. I could see the serial numbers in the frontend and the console, but their middleware just hated them.

I am using a USB multi-disk drive thing, which didn’t work properly on an old kernel, but it should have been fine with the new kernel.

I reported the bug, which didn’t really get addressed, and then had to build my array using the command line tools (which aren’t documented).

I dunno about recommending FreeNAS (Known as truenas now). It is basically an appliance OS, and unless you are using enterprise level hardware, they want nothing to do with you.

I’m currently using it, but it was a very unpleasant experience setting it up.