<font size=2 face="sans-serif">in addition ... </font><br><font size=2 face="sans-serif">depending on you block size and the
multi threaded NFS .. IO's may not come in the right order to GPFS so that
GPFS can't recognize sequential or random IO access patterns correctly...
</font><br><font size=2 face="sans-serif">therefore adjust: </font><tt><font size=3 color=#ff4040><b>nfs</b></font></tt><tt><font size=3>PrefetchStrategy</font></tt><font size=2 face="sans-serif"> default [0] to [1-10]</font><br><font size=2 face="sans-serif">it tells GPFS to consider all inflight
IOs as sequential with in this number of block boundaries.. </font><br><br><font size=2 face="sans-serif">consider further more: prefetchPCt /
pagepool </font><br><br><font size=2 face="sans-serif">to MFTC .. check by </font><tt><font size=3>mmfsadm
saferdump fs</font></tt><font size=2 face="sans-serif"> your current
utilization if you 're hit the limit or hoe many files or open.. </font><br><div><font size=2 face="sans-serif">Mit freundlichen Grüßen / Kind regards</font><br><br><font size=2 face="sans-serif"> <br>Olaf Weiser<br> <br>EMEA Storage Competence Center Mainz, German / IBM Systems, Storage Platform,<br>-------------------------------------------------------------------------------------------------------------------------------------------<br>IBM Deutschland<br>IBM Allee 1<br>71139 Ehningen<br>Phone: +49-170-579-44-66<br>E-Mail: olaf.weiser@de.ibm.com<br>-------------------------------------------------------------------------------------------------------------------------------------------<br>IBM Deutschland GmbH / Vorsitzender des Aufsichtsrats: Martin Jetter<br>Geschäftsführung: Martina Koederitz (Vorsitzende), Susanne Peter, Norbert
Janzen, Dr. Christian Keller, Ivo Koerner, Markus Koerner<br>Sitz der Gesellschaft: Ehningen / Registergericht: Amtsgericht Stuttgart,
HRB 14562 / WEEE-Reg.-Nr. DE 99369940 </font><br><br><br><br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">Bryan Banister <bbanister@jumptrading.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">10/17/2016 09:00 AM</font><br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">Re: [gpfsug-discuss]
CES and NFS Tuning suggestions</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><font size=2 color=#004080 face="Calibri">One major issue is the maxFilesToCache
and maybe the maxStatCache (though I hear that Linux negates the use of
this parameter now? I don’t quite remember). Ganesha apparently
likes to hold open a large number of files and this means that it will
quickly fill up the maxFilesToCache. When this happens the [gpfsSwapdKproc]
process will start to eat up CPU time. This is the daemon that tries
to find a file to evict from the cache when a new file is opened. This
overhead will also hurt performance. </font><br><font size=2 color=#004080 face="Calibri"> </font><br><font size=2 color=#004080 face="Calibri">IBM in a PMR we opened suggested
setting this to something like 5 Million for the protocol nodes. I
think we started with 1.5 Million. You have to be mindful of memory
requirements on the token servers to handle the total sum of all maxFilesToCache
settings from all nodes that mount the file system.</font><br><font size=2 color=#004080 face="Calibri"> </font><br><font size=2 color=#004080 face="Calibri">Of course the other, standard
NFS tuning parameters for number of threads and NFS client mount options
still should be adjusted too.</font><br><font size=2 color=#004080 face="Calibri"> </font><br><font size=2 color=#004080 face="Calibri">Hope that helps,</font><br><font size=2 color=#004080 face="Calibri">-Bryan</font><br><font size=2 color=#004080 face="Calibri"> </font><br><font size=2 face="Calibri"><b>From:</b> gpfsug-discuss-bounces@spectrumscale.org
[</font><a href="mailto:gpfsug-discuss-bounces@spectrumscale.org"><font size=2 face="Calibri">mailto:gpfsug-discuss-bounces@spectrumscale.org</font></a><font size=2 face="Calibri">]
<b>On Behalf Of </b>Oesterlin, Robert<b><br>Sent:</b> Sunday, October 16, 2016 7:06 PM<b><br>To:</b> gpfsug main discussion list <gpfsug-discuss@spectrumscale.org><b><br>Subject:</b> [gpfsug-discuss] CES and NFS Tuning suggestions</font><br><font size=3 face="Calibri"> </font><br><font size=2 face="Helvetica">Looking for some pointers or suggestions
on what I should look at changing in Linux and/or GPFS "mmchconfg"
settings to help boost NFS performance. Out of the box it seems "poor".</font><br><font size=2 face="Helvetica"> </font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Helvetica">Bob Oesterlin<br>Sr Storage Engineer, Nuance HPC Grid<br>507-269-0413</font><br><font size=3 face="Calibri"> </font><p><font size=3><br></font><hr><font size=1 color=#808080 face="Arial"><br>Note: This email is for the confidential use of the named addressee(s)
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