Original question: why does the "used+available" total from "swap -s" vary.
Answer: because virtual memory varies!
In Casper's own words...
> The total amount of virtual memory isn't constant.
>
> That may seem strange, but in Solaris 2.x the amount of virtual memory is
> teh amount of swap space plus the amount of RAM available to user
> processes. Any RAM on temporary assignment in the kernel will not show up.
rgds
Stephen