NFS mount fails CentOS5 on FC16 host

[Veli-Pekka Kestilä]

On 10.5.2012 20:44, Bill Davidsen wrote:
> Veli-Pekka Kestilä wrote:
>> 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
>>>>>
>>>
>>> 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.
>>
>> As how you get rid of the error before RedHat fixes the actual source 
>> (just make
>> the soft link between rpcidmapd and rpc.idmapd)
>>
> Adding the link solved the problem, although it's a kludge for sure!
Yeah.
>> 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.
>>
> And there, too, the most recent kernel upgrade made it work (although 
> the warning is still there without the link).
>
>> Hope this helps,
>> -vpk
>
> Looks right, the spurious warning issue is avoided for the moment, and 
> the failure of the mount is fixed (and hopefully added to regression 
> testing and will stay that way). Thanks for the work-around on the 
> warning, I had updated the kernel by the time I saw your message, 
> since I was watching closely for updates.
>
Good to hear. I didn't bother to fix the error. Only thing which I hated 
was that I thought first (like you did) that this error was caused by 
the failure of nfs-mount. But after little bit of searching around I 
found out it was unrelated. Then I actually managed to find the root 
cause. I actually thought of upgrading to CentOS6 for a while because of 
that.

One thing I learned from this is that one can't trust even RH to 
actually test the core features of the releases in automated way. And 
that I am really happy to have a test server as it really (even as a 
virtual machine) saves you from sleepless nights. :)

-vpk