I have a simple html website that is a few years old and has achieved a good pagerank for certain keywords and phrases. I'm about to launch a completely new site to replace it. The new site uses Magento and resides on a different host than the original site.

If this was just a domain name transfer, it would be simple. However, with the new structure and pages of the Magento site, what other measures I should take to ensure that I lose as little traffic and pagerank as possible during the transition, for example:

- Using 301 redirects for each and every page of the old site to the equivalent pages on the new site.

- Move the old site files to the new host and run the old site concurrently with the new site, linking the former to the latter.

- Leaving the old site active and running the new site on a subdomain linked to the old site.

I've replicated much of the content from the old site to the new one and will use

the same url's for those pages. I'd appreciate any advice. Thanks.