If your goal is having a backup (second site) of your first install (production site) for development or testing proposes. Something you want play with and not damage your first install (production site), then it's quite easy.
1. install phpmyadmin on both machines.
2.backup your db with phpmyadmin (or command line) on first machine.
3.backup your prestashop installation on first machine.
4.restore your db on second machine with phpmyadmin (or command line)
5.restore your prestashop installation on second machine
6.access your db on second machine, edit ps_configuration : PS_SSL_ENABLE 0 "<-- 1 ( 0=off 1=on)"
7.access your db on second machine, edit ps_shop_url :
domain : www.domain.com <> localhost
domain : www.domain.com <> localhost
physical_uri: /xxxx/ "<-- if not rooted"
8.login to your prestashop Back Office aka admin page
9.go to Advanced Parameters / Performance and hit Clear Cache (you can manually wipe ~/var/cache/dev and ~/var/cache/prod if you prefer)
10.go to Shop Parameters / Traffic & SEO / Set up URLs > enable Friendly URL and hit Save this will regenerate .htaccess file on your second machine.
hope this helps mirroring/backing up/duplicating your first install on another machine.