From: Ara.T.Howard@...
Date: 2004-08-27T00:00:38+09:00
Subject: Re: [OT] nfs lockd recovery - was Re: POLS - exception comparisons

On Thu, 26 Aug 2004, Martin DeMello wrote:

> Ara.T.Howard@noaa.gov wrote:
>>
>> it's figured out.  i have it coded in a nice and ugly fashion and have been
>> testing it for the last 24 hours with a bit of code that 'breaks' to lock
>> every few seconds and forces recovery in the clients.  note that the
>> entire thing is an emergency only procedure that takes place ONLY when
>> the system is already broken (hung locks) and so the solution doesn't
>> have to be 'perfect'.
>
> Interesting. Did it turn out to be a known feature of nfs causing the
> hung locks, or is it a genuine bug?

a genuine bug - supposedly fixed in future rh kernels, but we are stuck using
the latest 'official' rh kernel which does contain it.  also, from talks on
the nfs list, i've determined that it's not an uncommon problem - one that
people that make heavy use of nfs see from time to time in various impl.
becuase of that, it's best just to be prepared for it.  in 4 months of running
my code i've seen it happen only once, but it's a bit of deal breaker.  in the
end, even an attempt to resolve it is better than nothing since code
experiencing it is already broken.

regards.

-a
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