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I haven't posted novels or novellas myself, but from what I hear, finding a group where you can trade reviews with likeminded writers is pretty much the only way to go (or finding one or more critique partners, but that's essentially the same thing).
Simply posting the chapters probably won't get you many reviews, at least not useful ones, and those you do get will probably be of the first chapters only. Offering GPs doesn't seem to help either.
There's the WYRM group for speculative fiction, and I know there's a general novel critique group somewhere as well. There are probably groups for other genres as well.