mount – How to export an NFS mounted drive to nfsd in Linux (i.e. NFS proxy server)?


Suppose there is a server 1.1.1.1 that runs NFS server version 4.0 or above, and I need to access some files on the server from a computer 2.2.2.2 that runs NFS client version 3.0 or below. So what I want to do is to setup a proxy server at 3.3.3.3.

Suppose the file I need to access is at 1.1.1.1:/path1/a.txt, and in 3.3.3.3 I do:

mount 1.1.1.1:/path1/ /path3/path1/

So now I can access the file through 2.2.2.2:/path3/path1/a.txt

In 2.2.2.2:

mount 3.3.3.3:/path3/ /path2/path3/

After that, the path 2.2.2.2:/path2/path3/path1 appears to be empty. Why is it happening? How can I fix it?