> As to different priorities on swap, that doesn't seem > to make much practical sense. It would tend to force > all your paging to a single device.
If you have different speed devices, it allows you to set up a hierarchy. Think solid-state disk, fast 3390 disk, old 3380s as a possible scenario. You get balancing between swap areas at the same priority, and as you move down the food chain you get to group what resources get used in what order.
