[Zope] Zope file system and scalability

[sree]

Dear friends,
Greetings!

I am trying to build a huge extranet using zope where there will be 
large amount of messageing and file shareing.

How scalable is Zope object file system. I was told zope has to keep 
complete zope data.fs in memory so as to work. Is this true. Are there 
any further reference articles on this.
As part of the project i need to enable users to upload the work files 
such as StarOffice clac files, word documents and pdf. If they use to 
file object in zope then the file gets embedded to zope data.fs making 
it enormously huge. Is this preferable. or should i try loacl fs. Any 
help in this will be of immence value.

Regards,
  -  sree