NFS mount fails CentOS5 on FC16 host

[Veli-Pekka Kestilä]

On 10.5.2012 0.40, Bill Davidsen wrote:
> Ed Greshko wrote:
>> On 05/09/2012 10:26 PM, Bill Davidsen wrote:
>>> I get a message "rpc.idmapd appears not to be running" when it is 
>>> running, and I'm
>>>
>>> mount is "rw,soft,intr -t nfs4" and the idmap process is running on 
>>> host and
>>> client, remounts from other clients work, etc, etc.
>> It isn't clear to me from the above what system is the Client and 
>> what system is the
>> Server and on which system you're getting the error message.
>>
> Sorry, I intended the subject to make that clear, the client is 
> CentOS-5 the server FC16. The message appears on the CentOS5 client. 
> The same server and data works on clients running FC9, FC10, FC13, 
> RHEL-6, and I believe (ie. I'm told but haven't personally tested) 
> OpenBSD works as well.
>
> This is the only machine which stopped working when the NFS server was 
> updated, and of course it's the internal web server. :-(
>
I had lot of problems with NFSv4 and CentOS 5.8, you should check that 
you have latest kernel on 5.8 as that solved some mounting problems. As 
for the error messages telling rpc.idmapd not running you can safely 
ignore. The error comes from the mount.nfs4 trying to read file in var 
which is not in there.

If you run strace mount.nfs4 server:/ /dir you will see that the command 
tries to access /var/lock/subsys/rpcidmapd
access("/var/lock/subsys/rpcidmapd", F_OK) = -1 ENOENT (No such file or 
directory)
This doesn't work as the file is actually named /var/lock/subsys/rpc.idmapd
As how you get rid of the error before RedHat fixes the actual source 
(just make the soft link between rpcidmapd and rpc.idmapd)

Now to the real error, I had the mounting problems from CentOS 5.8 to 
CentOS 5.8 with CLIENT running with kernel 2.6.18-308.1.1.el5 mounting 
didn't work. As I had the older kernel around as this was upgrade from 
older 5.x release I tried with it and the things worked without a 
problem. RedHat fixed the problem for me atleast in kernel 
2.6.18-308.4.1.el5.

Hope this helps,
-vpk