The box is a SuperMicro 6015B-Ni with XDBU mobo; if I change (in BIOS):
Main > Native Mode Operation > Auto for Main > Native Mode Operation > Serial ATA, all works fine. So, OpenBSD doesn't support this BIOS option and you have to specificate it if you use SATA disk (as my own case). I hope it will be useful for someone. -- Thanks, Jordi Espasa Clofent
