in reply to
Re^3: LWP::Simple Getstore memory
in thread LWP::Simple Getstore memory
You were using LWP::Simple, it's simple interface to LWP::UserAgent.
But LWP::UserAgent (which have content_file option) is not "Simple" it's full version.
Also I believe this comment Re: LWP::Simple Getstore memory probably correct, and getstore should not eat so much memory. It looks like it's implemented same way as content_file option.