Re: Permission denied when mounting NFS (was okay before)

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Fri, 2008-09-26 at 23:57 +0800, howard chen wrote:
> Hi,
> 
> On Fri, Sep 26, 2008 at 11:25 PM, Talpey, Thomas
> <Thomas.Talpey@netapp.com> wrote:
> > At 11:05 AM 9/26/2008, howard chen wrote:
> > You didn't indicate what the client and server were, btw.
> 
> client is 3, as I see when mount with verbose option: ... mount:
> trying xxxx prog 100003 vers 3 prot udp port 2049
> 
> server should be also 3, default by CentOS 4.4, 64bit

What does

  'rpcinfo -p 10.10.10.1'

give you? Also,

  'showmount -e 10.10.10.1'

Finally, what kind of filesystem are you exporting on /data0/tmp?

> >
> > Do you have multiple interfaces on the client? If the client routing
> > originates from a different address than 10.10.10.2, then the server
> > will deny it because you have specified a numerical address.
> 
> Yes, both servers have interface for public IP, but as I can see the
> 10.10.10.2 in /var/log/message of NFS server, so I think routing is
> ok.
> 
> 
> 
> > This isn't the source of the permissions error, but why are you doing
> > a UDP mount, and with only three retries? Generally, TCP will perform
> > better, and more robustly. Also, the "noatime" option is a no-op for
> > the NFS client (servers are in charge of maintaining atime).
> 
> I agree TCP is more robust, but isn't UDP will have a better performance?

That depends. In my experience, the difference in performance on an
unloaded network, then UDP will outperform TCP by ~10%. However, if you
have a heavily loaded network with lots of dropped packets, then TCP
will usually give much better performance than UDP.

Trond