Redhat OS and Filesystem for billions of Small Files

Hi

I would like to know which type of Filesystem will be best for the following requirements:

file size: ~2KB to 5MB
Number of small files: In 100 of millions
Number of Directories: In 100 of millions
Partition Size: ~400TB
Data Pattern: Continuous Write 70%, Continuous Read 30%, Continuous Deletion 20%.

Thanks and Best Regards

Mansoor