Doubt in AIX and HP-UX disk devices addressing

Hi people,

Does anyone know how the AIX form the hdisk addresses ? I mean, if the AIX use the SAN fields like switch id, domain id, port id and etc...

After I understand that my next question is: Why the AIX do not change the hdisks addressing if I change the AIX HBAs of the SAN switch and/or switch ports in the same SAN fabric and the HP-UX usually change the cxtxdx disk device addressing ? I whold like understand these points and how the AIX and HP-UX make the disk device addresses.

Thanks in advance!

Although I could answer for AIX I will leave that for the AIX gurus...
HP:
1) Changing HBA for the same in the same slot doesnt affect your disks since you are replacing the controller for another in the same slot (that's the cX).
2) changing port or switch will affect your disks since it uses for its ID the SAN WWN.