[CentOS] inquiry about limitation of file system

I have a website with millions of pages. We often deploy our websites on centos with Nginx and Apache Http Server as HTTP Web Server. I am very worried about the performance of web server if the amount of pages is very very large. I wonder whether the performance will be affected if there are too many files and directories on the server. Besides, our bugdet is limited. We do not want to deploy too many Servers and use other file system such as GFS. So I want to know the limitation of centos file system and how should I handle this issue.