<font size=2 face="sans-serif">I have no practical experience on these
numbers, however, Peters experience below is matching what i learned from
Dan years ago.</font><br><br><font size=2 face="sans-serif">As long as the -n setting of the FS
(the number of nodes potentially mounting the fs) is more or less matching
the actual number of mounts, </font><br><font size=2 face="sans-serif">this 99.x % before degradation is expected.
If you are far off with that -n estimate, like having it set to 32, but
the actual number of mounts is in the thousands,</font><br><font size=2 face="sans-serif">then degradation happens earlier, since
the distribution of free blocks in the allocation maps is not matching
the actual setup as good as it could be. </font><br><br><font size=2 face="sans-serif">Naturally, this depends also on how
you do filling of the FS. If it is only a small percentage of the nodes,
doing the creates, then the distribution can </font><br><font size=2 face="sans-serif">be 'wrong' as well, and single nodes
run earlier out of allocation map space, and need to look for free blocks
elsewhere, costing RPC cycles and thus performance. </font><br><br><font size=2 face="sans-serif">Putting this in numbers seems quite
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Deutschland GmbH / Vorsitzender des Aufsichtsrats: Martin Jetter <br>Geschäftsführung: Martina Koederitz (Vorsitzende), Reinhard Reschke, Dieter
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HRB 14562 WEEE-Reg.-Nr. DE 99369940 </font></table><br><p><font size=3> </font><br><br><br><br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">Peter Smith <peter.smith@framestore.com></font><br><font size=1 color=#5f5f5f face="sans-serif">To:
</font><font size=1 face="sans-serif">gpfsug main discussion
list <gpfsug-discuss@spectrumscale.org></font><br><font size=1 color=#5f5f5f face="sans-serif">Date:
</font><font size=1 face="sans-serif">11/06/2017 09:17 AM</font><br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">Re: [gpfsug-discuss]
Performance of GPFS when filesystem is almost full</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=3>Hi Carl.<br></font></tt><br><tt><font size=3>When we commissioned our system we ran an NFS stress
tool, and filled the system to the top.<br></font></tt><br><tt><font size=3>No performance degradation was seen until it was 99.7%
full.<br></font></tt><br><tt><font size=3>I believe that after this point it takes longer to
find free blocks to write to.<br></font></tt><br><tt><font size=3>YMMV.</font></tt><br><br><font size=3>On 6 November 2017 at 03:35, Carl <</font><a href=mailto:mutantllama@gmail.com target=_blank><font size=3 color=blue><u>mutantllama@gmail.com</u></font></a><font size=3>>
wrote:</font><br><font size=3>Hi Folk,</font><br><br><font size=3>Does anyone have much experience with the performance
of GPFS as it becomes close to full. In particular I am referring to split
data/meta data, where the data pool goes over 80% utilisation. </font><br><br><font size=3>How much degradation do you see above 80% usage, 90% usage?</font><br><br><font size=3>Cheers,</font><br><br><font size=3>Carl.</font><br><br><br><font size=3><br>_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at </font><a href=http://spectrumscale.org/ target=_blank><font size=3 color=blue><u>spectrumscale.org</u></font></a><font size=3 color=blue><u><br></u></font><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss" target=_blank><font size=3 color=blue><u>http://gpfsug.org/mailman/listinfo/gpfsug-discuss</u></font></a><font size=3><br></font><br><font size=3><br><br><br>-- </font><br><font size=3 color=#4181c0><b>Peter Smith</b> · Senior Systems Engineer<b><br>London</b> · New York · Los Angeles · Chicago · Montréal</font><font size=3><br>T +44 (0)20 7344 8000 · M </font><a href="tel:+44%20%280%297816%20123009" target=_blank><font size=3 color=#0082bf>+44
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