NFS Filesystem

[Manoj P.U.]

Hi Gurus,

I am not sure whether my question is proper or not.

Is it possible to do NFS mount another exported NFS filesystem?

For example:
1. Server-A, acting as NFS server.
/abc directory is exported on server-A.

2. Server-B, Acting as NFS client and NFS server.
NFS mounted Server-A:/abc on /xyz of Server-B and exported /xyz.

3. Server-C, Acting as NFS client wants to mount Server-B:/xyz on /mnt of Server-C.

Is this possible?

Thanks in advance
Manoj

[Patrick Wallek]

I just tried exporting an NFS mounted filesystem and got the error "Too many levels of remote in path". That tells me that this is not going to work.

I'm not sure why you would want to do this anyway. This would add an unneeded level of complexity.

Just have server-c mounted the exported filesystem from server-a. You will accomplish the same thing.

[Mel Burslan]

What you are suggesting is not supported and not recommended. It may work under special circumstances with a bit of networking devices help but you will only be able to read from these devices. Writing to them through cascaded NFS mounts will be impossible.

[Manoj P.U.]

Hi Patrik/Mel,

You are right, I am making it more complex.

I am working away from the our servers. I am trying install a software, which is in CD with SD-UX format.

I have mounted my desktop cdrom on a linux server with linux samba option.

hp server comes out with error when I try to mount linux exported filesystem on hp server.

Best Regards,
Manoj

[Mel Burslan]

In this case, I am assuming you can scrape up a 700MB free space somewhere on this linux machine, copy the contents into a local directory and NFS export from that point. When PC and SAMBA come into action, all bets are off. I am not even sure you can do this type of cascading.

[Dave Olker]

Allowing an NFS client to export a filesystem it mounted from an NFS server would be a violation of the NFS security model. Yes, believe it or not, NFS does have *some* security. One of the most basic tenents of NFS security is: the server decides who gets access to its resources.

That is why you cannot have a client NFS mount a server's filesystem and then re-export it - this would be allowing the NFS client to make access decisions instead of the server who owns the local filesystem.

Regards,

Dave