Hey all,
I was once again wondering which metric to use for memory capacity planning. Since informations from different sources (e.g. Your ESXi Host needs more RAM from Iwan Rahabok or VMworld 2012: Session VSP1729 - Understanding Virtualized Memory Performance Management - Eric Sloof - NTPRO.NL from Kit Colbert) all pointing to Active (Demand in vROPS), I was expecting that when we have high memory consumption / usage in vCenter there will be no ballooning / compression / swapping.
Also the metric active/demand shouldnt be used for all workloads (e.g. Java / DB), why is that? I didnt find the reason for that anywhere, only the fact.
Other sources like suggest to use consumed/usage, thats the opposite (Understanding vSphere Active Memory - VMware vSphere Blog - VMware Blogs).
So I thought I go with active/demand as metric and ignoring the warnings inside vCenter.
But last time we patched the half of our cluster we had high consumed/usage of memory and the vCenter started to balloon, compress and finally swap. Not much but I wasnt expecting that, because active memory was only a small percentage of consumed.
Can someone explain me, why this happened and who is right regarding this questions.
Kind regards,
jengl