<font size=3 face="Arial">What is in the dump that indicates the metanode
is moving around? Could you please provide an example of what you
are seeing?</font><br><br><font size=3 face="Arial">You noted that the access is all read only,
is the file opened for read only or for read and write?</font><br><br><font size=3 face="Arial">What makes you state that this particular
file is interfering with the scan done by mmbackup? Reading a file,
no matter how large should significantly impact a policy scan.</font><br><br><font size=3 face="Arial">What version of Spectrum Scale are you running
and how large is your cluster?</font><br><br><font size=2 face="sans-serif">Regards, The Spectrum Scale (GPFS) team<br><br>------------------------------------------------------------------------------------------------------------------<br>If you feel that your question can benefit other users of Spectrum
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for priority messages to the Spectrum Scale (GPFS) team.</font><br><br><br><br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">Peter Childs <p.childs@qmul.ac.uk></font><br><font size=1 color=#5f5f5f face="sans-serif">To:
</font><font size=1 face="sans-serif">"gpfsug-discuss@spectrumscale.org"
<gpfsug-discuss@spectrumscale.org></font><br><font size=1 color=#5f5f5f face="sans-serif">Date:
</font><font size=1 face="sans-serif">07/10/2018 10:51 AM</font><br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">[gpfsug-discuss]
Same file opened by many nodes / processes</font><br><font size=1 color=#5f5f5f face="sans-serif">Sent by:
</font><font size=1 face="sans-serif">gpfsug-discuss-bounces@spectrumscale.org</font><br><hr noshade><br><br><br><tt><font size=2>We have an situation where the same file is being
read by around 5000<br>"jobs" this is an array job in uge with a tc set, so the file
in<br>question is being opened by about 100 processes/jobs at the same time.<br><br>Its a ~200GB file so copying the file locally first is not an easy<br>answer, and these jobs are causing issues with mmbackup scanning the<br>file system, in that the scan is taking 3 hours instead of the normal<br>40-60 minutes.<br><br>This is read only access to the file, I don't know the specifics about<br>the job.<br><br>It looks like the metanode is moving around a fair amount (given what I<br>can see from mmfsadm saferdump file)<br><br>I'm wondering if we there is anything we can do to improve things or<br>that can be tuned within GPFS, I'm don't think we have an issue with<br>token management, but would increasing maxFileToCache on our token<br>manager node help say?<br><br>Is there anything else I should look at, to try and attempt to allow<br>GPFS to share this file better.<br><br>Thanks in advance<br><br>Peter Childs<br><br>-- <br>Peter Childs<br>ITS Research Storage<br>Queen Mary, University of London<br>_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at spectrumscale.org<br></font></tt><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss"><tt><font size=2>http://gpfsug.org/mailman/listinfo/gpfsug-discuss</font></tt></a><tt><font size=2><br><br></font></tt><br><br><BR>