I'm developing a web platform that may reach some million of users where I need to store users' images and docs. I'm using Rackspace and now I need to define the files logic into cloud files service. Rackspace allows to create up to 500,000 containers with an account (reference page 17, paragraph 4.2.2) and in addition they suggest to limit each container size up to 500,000 objects (reference Best practice - Limit the Number of Objects in Your Container), which is the best practice for users files management?
One container for user don't seems to be a good solution because there is the 500,000 containers limit. Rackspace suggests to use virtual container. I'm a bit undecided how to use them.
Thanks in advance.