<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Restarting subnet manager in general is fairly harmless. It will cause a heavy sweep of the fabric when it comes back up, but there should be no LID renumbering. Traffic may be held up during the scanning and rebuild of the routing tables. <div> Losing a subnet manager for a period of time would prevent newly booted nodes from receiving a LID but existing nodes will continue to function. <div>Adding or deleting inter-switch links should probably be avoided if the subnet manager is down. I would also avoid changing the routing algorithm while in production. </div><div>Moving a non ha subnet manager from primary to backup and back again has worked for us without disruption, but I would try to do this in a maintenance window. <br><br><div id="AppleMailSignature" dir="ltr"> -- ddj<div>Dave Johnson</div></div><div dir="ltr"><br>On Sep 13, 2019, at 4:48 AM, Lehmann, Greg (IM&T, Pullenvale) <<a href="mailto:Greg.Lehmann@csiro.au">Greg.Lehmann@csiro.au</a>> wrote:<br><br></div><blockquote type="cite"><div dir="ltr">
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<p class="MsoNormal"><span lang="EN-AU">Hi All,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU"> I was wondering what effect restarting the subnet manager has on an active Spectrum Scale filesystem. Is there any scope for data loss or corruption? A 2<sup>nd</sup> similar scenario of slightly longer
duration is failover to a secondary subnet manager because the primary has crashed. What effect would that have on the filesystem?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-AU" style="color:#00A9CE">Greg Lehmann</span></b><span lang="EN-AU" style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU" style="font-size:9.0pt;color:black">Senior High Performance Data Specialist<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-AU" style="font-size:9.0pt;color:black">Data Services | Scientific Computing Platforms<o:p></o:p></span></p>
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<p class="MsoNormal"><u><span lang="EN-AU" style="font-size:9.0pt;color:black"><a href="mailto:Greg.Lehmann@csiro.au">Greg.Lehmann@csiro.au</a></span></u><span lang="EN-AU" style="font-size:9.0pt;color:black">
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