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<p class="MsoNormal">@Aaron<o:p></o:p></p>
<p class="MsoNormal">Yes, I can confirm that 2MB blocks are transfered over.<br>
<br>
<o:p></o:p></p>
<p class="MsoNormal">@ Jan-Frode<o:p></o:p></p>
<p class="MsoNormal">We tried to change multiple parameters, but if you know the best combination for sequential IO, please let me know.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">#mmlsconfig<o:p></o:p></p>
<p class="MsoNormal">autoload no<o:p></o:p></p>
<p class="MsoNormal">dmapiFileHandleSize 32<o:p></o:p></p>
<p class="MsoNormal">minReleaseLevel 5.1.9.0<o:p></o:p></p>
<p class="MsoNormal">tscCmdAllowRemoteConnections no<o:p></o:p></p>
<p class="MsoNormal">ccrEnabled yes<o:p></o:p></p>
<p class="MsoNormal">cipherList AUTHONLY<o:p></o:p></p>
<p class="MsoNormal">sdrNotifyAuthEnabled yes<o:p></o:p></p>
<p class="MsoNormal">pagepool 64G<o:p></o:p></p>
<p class="MsoNormal">maxblocksize 16384K<o:p></o:p></p>
<p class="MsoNormal">maxMBpS 40000<o:p></o:p></p>
<p class="MsoNormal">maxReceiverThreads 32<o:p></o:p></p>
<p class="MsoNormal">nsdMaxWorkerThreads 512<o:p></o:p></p>
<p class="MsoNormal">nsdMinWorkerThreads 8<o:p></o:p></p>
<p class="MsoNormal">nsdMultiQueue 256<o:p></o:p></p>
<p class="MsoNormal">nsdSmallThreadRatio 0<o:p></o:p></p>
<p class="MsoNormal">nsdThreadsPerQueue 3<o:p></o:p></p>
<p class="MsoNormal">prefetchAggressiveness 2<o:p></o:p></p>
<p class="MsoNormal">adminMode central<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">/dev/fs0<br>
<br>
<o:p></o:p></p>
<p class="MsoNormal">@Uwe<o:p></o:p></p>
<p class="MsoNormal">Using iohist we found out that gpfs is overloading one dm-device (it took about 500ms to finish IOs). We replaced the „problematic“ dm-device (as we have enough drives to play with) for new one but the overloading issue just jumped to another
dm-device.<br>
We believe that this behaviour is caused by the gpfs but we are unable to locate the root cause of it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#595959;mso-fareast-language:CS">Best,<br>
Michal<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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