i'm trying to find the best solution to create scalable storage for big files. File size can vary from 1-2 megabytes and up to 500-600 gigabytes. 

I have found some information about Hadoop and it's HDFS, but it looks a little bit complicated, because i don't need any Map/Reduce jobs and many other features. Now i'm thinking to use MongoDB and it's GridFS as file storage solution.

And now the questions:

1. What will happen with gridfs when i try to write few files
 concurrently. Will there be any lock for read/write operations? (I will use it only as file storage)
2. Will files from gridfs be cached in ram and how it will affect read-write perfomance?
3. Maybe there are some other solutions that can solve my problem more efficiently?

Thanks.