I want to install and use prestashop but now it only works correctly when I set permissions to 777 (I can login to the server via shell with root privileges). While installing I get this error "recursive write permissions for apache user on..." and only works for permissions set to 777. I don't like this idea because after installation I can't even change back to 755 or 775. I also get problem partly solved when I change the user ownership to apache but then I can't do anything with my ftp client with that folder.
The user owner is ftp and the group owner is psacln? How should I change the membership of the folders so I can work both through ftp and allow apache to do things with presta files? (and of course have the permission set not higher then to 775). BTW, do I have to restart a server when adding or removing user's membership of the group?
This should fix your problem.
ssh root@ip_address
chown -R www-data:ftp /var/www/prestashop
You don't need to restart the server.
Optional : service apache2 reload