[gpfsug-discuss] Potential problems - leaving trace enabled in over-write mode?

[Steve Duersch]

You are correct.  There is some level of tracing on the v7000U.
Also, if the gpfs daemon hits an assert or signal and tracing is running
then traces are recycled automatically.  There is no need to have another
script monitoring for such events.  You probably want to have mmtracectl
--trace-recycle=global so that an assert on one node grabs traces on all
nodes (ie fs manager).
As for performance, this one is more difficult and I don't have details.  I
can ping a colleague to see if he has numbers.  Obviously there will be a
performance penalty for running tracing.


Steve Duersch
Spectrum Scale
IBM Poughkeepsie, New York




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>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 7 Mar 2017 21:11:33 +0000
> From: "Oesterlin, Robert" <Robert.Oesterlin at nuance.com>
> To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
> Subject: Re: [gpfsug-discuss] Potential problems - leaving trace
>    enabled in over-write mode?
> Message-ID: <FF476173-947E-461F-8223-CD0334E60FB1 at nuance.com>
> Content-Type: text/plain; charset="utf-8"
>
> I?ve been told that V70o0 unified nodes (GPFS under the covers) run
> with tracing enabled all the time.. but I agree with you Brian on
> the potential impacts. But when you must catch a trace for a problem
> that occurs once every few weeks ? how else would I do it?
>
> Bob Oesterlin
> Sr Principal Storage Engineer, Nuance
> 507-269-0413
>
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