Of course (on Linux, anyway) the default partition scheme only uses one drive.
Presuming Linux, here's what I'd do on that system (without RAID):
On the first drive:
Then the balance as a single LVM partition.
On the second drive:
Code:
/var 15 G
/tmp 2 G
<swap> 1G
Then the balance on a single LVM container.
And on the third drive a single LVM container.
Then with the LVM containers I'd create a single logical partition
home in this order:
3rd drive's LVM + 3rd drive's LVM + 1st drive's LVM
Then on that logical partition I'd create the /home directory using all the remaining space.
With RAID it gets a bit more complex; you can create one RAID4 array with all three drives, then on that create a single LVM, and on that LVM create the partitions sized as above, using the same sizes, with /home defined last to take all the remaining space.
Jeff