Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Wed, 29 May 2013 17:43:50 -0500

Hi Lewis,

On 2013-05-29 J. Lewis Muir wrote:
> The error looks like it's coming from the autosave module.  I'm guessing
> maybe the RPC error suggests something wrong with communicating with the
> NFS server where the auto_settings.sav file is being written, but I
> don't know.  The NFS server log doesn't show any problem.  Once the
> problem starts, it doesn't seem to go away until I reboot the IOC.

Once it has started, does an 'ls' (or any other file operation) at the IOC 
console work against the NFS disk?

> This problem has not always existed; it used to work fine.  I initially
> thought it was a problem with autosave 5-0, since it seemed the problem
> showed up for the first time after I had upgraded to 5-0.  But then I
> rolled back to 4-8, and the problem is still appearing.  It's possible
> the NFS server changed somehow, or maybe a network adapter, cable,
> switch, etc. is failing, or none of these.

We have seen other problems ('ls' failing) against a Linux NFS server when 
using NFSv3, but this problem goes away if we revert back to NFSv2.  You can 
select the NFS version if you're mounting the drive manually, just use the 
nfs2Mount (or nfs3Mount) command instead of nfsMount.  However autosave calls 
nfsMount automatically in some cases which Tim Mooney can explain (probably 
related to I/O failures) and that could undo the manual mount.

I would prefer to fix the problem inside the NFSv3 code, but that could take 
some time so in the meanwhile I've produced some OS images that don't contain 
the NFSv3 client.  I can send you a copy of the mv5100 image if you want to 
see if that helps.

- Andrew
-- 
It is difficult to get a man to understand something, when his salary
depends upon his not understanding it. -- Upton Sinclair

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System