Solaris 10 x86 primary slave disk not detected

Dear all,

I try to have 6 SATA disks on one x86 machine. However, the
primary slave disk cannot be detected. The disk can be
detected and functioned whatever SATA number other than
being a primary slave. And I think that other disks can not
be primary slave disk.

Is it correct or not? How to fix this problem?

Thanks in advance.

--
Johnson Chow
.