> It works fine with 10 million links. Maximum memory
> amount of used during scanning (300000 links
> found)and memory usage is not over 100mb. With 30
> million links : it eats up 1 gb memory(all free
> memory i have) when starting scanning(scanning
> itself wont start). 
> 
> I really hope that I can handle with 5 million
> links, but a little bit overhead won't be bad,
> because running mirroring twice, because there were
> some more links to scan is a ridiculous thing

Your numbers don't make sense to me and you don't say why it wont start.

I ran a site with 47K links. It ran in 304MB virtual.  That's ruffly 7KB per
link.

Where did you get that 100mb figure? If it was task manager/Mem Usage that's
what's in RAM, not total (look at VM Size instead.)

300K links should require 2100MB and 30 million should require 21GB. What is
your virtual memory settings?