Strategy for large cache sets

[Skye Poier Nott]

I want to deploy Varnish with very large cache sizes (200GB or more)  
for large, long lived file sets.  Is it more efficient to use large  
swap or large mmap in this scenario?

According to the FreeBSD lists, even 20GB of swap requires 200MB of  
kern.maxswzone just to keep track of it, so it doesn't seem like that  
will scale too well.  Is one or the other method better for many small  
files vs less many big files?

Thanks again... when I'm a Varnish expert I'll help the newbs :)

Skye