How to use an external USB3.0 drive with 4k sectors?

Fri Jun 1 10:00:54 UTC 2012

> I have recompiled the kernel with "device ada" and put ahci_load="YES" in
> /boot/loader.conf.

you don't need ada driver for USB disk. anyway you need it for your SATA 
disk to make things fast.

> and mounting it works. Obviously, for the disk the device nodes aren't created...
> Is there something different between umass sticks and umass drives?
lost of USB devices are not really standard compliant.