I mounted a NFS share to a local mount point on my workstation and attempted to share the mount point with the NFS share out(firewall issues). My issue is that when any system mounts my workstation's NFS share it mounts fine but nothing is in the directory. What gives here and is it even possible to perform a double NFS mount?

Are you using NFS version 4? Look at the man exports man page. In particular the mountpath=/<path> option which won't export the path unless it has a mounted filesystem on it. I think that you may be exporting the directory before the file system is mounted on it.

The exported file system off the workstation has the exported NFS share from another server mounted fine. I'm using NFS3.

Taking a look at the manpage, I see that since I used nfs as the filesystem, I am using nfs v3 mode. The mountpoint= & mp= options in /etc/exports should work for nfs v3 from my reading of my manpage. It sounds like it helps prevent having an export mounted over (on the middle server) because the end client was mounted the directory before the mount on the originating server took place. If that could happen, then it could be a matter of timing whether you see the files on one end client but not another.

You might try a bit of an experiment. Touch a file in the directory you use as the mount point (that is also exported). On a system where this would appear empty, does that test file show up? If it does, the only way that can be the case is if the unmounted directory is being shared.

I'm also curious what the files in /proc/fs/nfsd/ show on a client where this mount is working and where it isn't. A bit beyond my depth here, but I wonder if the FSID differs (assuming it is remotely defined).

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Other than that, I don't know enough of the details of how nfs & the rpc's work on such an indirect share. Could the firewall cause a problem. I would think that if that was the case you would get access errors instead of seeing an empty directory. But would the original server (or the firewall in between) operate with rpc calls from the middle server or or the one on the end.

I have similar requirements, want to mount a mountpoint at middle server eventual point to another physical server, like: server A(mount)-->server B(mount)-->server C.

Any solution? pls help.

There migh be, jerryliu...why don't you look in your other thread, and don't hijack someone elses. This thread is over a year old, and not yours.