[Zope] Scalability

This is probably falls under the catagory of FAQ but I couldn't find a good answer through searching, so I'll ask. Are there any size limitations on file system storages? At what point can things become very slow? I'm wondering as much about the number of objects stored as well as file size for a Data.fs. And what about zeo storages. Is there on the number of zeo storages that can be connected to zope clients? As far as number of objects, I'm thinking in terms of 10,000,000 or more folderish and content objects. While I'm talking about it, are there any performance limitations on the zcatalog? Will it perform well even with this many objects? Thank you in advance, Kevin