primary/secondary disk question !!

Need to know the following....

1. Using what command I can get........" from which disk the system is booted off "

(primary or secondary or mirrror ... whatever)

2. using which command I can find out which is the primary boot disk

and which one is the secondary boot disk

OR

Before installing OS in a brand new system with more than one disk connected ,

which pattern we can use to select or identify the primary and secondary disk

thank you

[508 byte] By [VCP] at [2007-11-25 23:14:13]