Can anybody tell me how to predefine hardware resources, required for web hosting. This definately depends on the nature of the web sites hosted, size of the customer base, database usage & many other factors. Still, it may be possible to provide a general description using some scenarios. For example, what is the server requirement for hosting 100 middle-sized websites on linux platform in shared hosting base? What may the requirement, if these web-sites use MySQL databases? & so forth.

Pls suggest, many thanks.