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<p>hi all,</p>
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<p>All my vSphere (ESXi5.1) hosts experience a big spike in latency every hour or so.</p>
<p>I tested on Infiniband iSER and SRP and also 4Gbit FC and 8GBit FC. All exhibit the same behavior so I don't think its the connection that is causing this.</p>
<p>When I modify the arc_shrink_shift 10 (192GB Ram in the System) it helps a bit, the spikes are still with the same regularity but latency peaks at about ~5000ms for the most part. if I leave arc_shrink_shift at the default value they can be higher - up to
15000ms.</p>
<p>Looking at the latency as seen from the vSphere hosts the average is usually below 1ms for most datastores.</p>
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<p>Any ideas what can cause this or what can be done to fix?</p>
<p>br,</p>
<p>Rune</p>
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