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Pille66
Contributor
Contributor

high memory utilization on vCenter

hello all

for testing and learning purpose i build a ESX Cluster.

vCenter = VMware-VIM-all-6.5.0-5318154

esxi 6.5 = latest download

3 esxi hosts (in eval mode), also the vcenter is in eval mode

if the esxi hosts are installed and i connect per webinterface the the hosts i see the memory consumption are round about 1.5 gb (each of the 3)

if i add it to the vcenter cluster the ram utilization on the esx hosts goes up to 12 gb.

there is nothing configured on the esx (except the IP) and the vCenter is without any config as well.

as i wrote this i discovered following

all 3 hosts i installed new (and connected to the vcenter) - started with 1.5 gb memory usage

added 1 distributed switch (added the hosts) - each host increase the memory to 1.6 gb

i added a second - still 1.6 gb

added a 3th - memory consumption went up to 1.75 gb ram (on all 3 hosts)

i keep the list updated ....

is that normal ?

can somebody tell me something about.

i have seen a couple of esx host but never such resource hungry - is that an feature of the version 6.5 ?

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4 Replies
vijayrana968
Virtuoso
Virtuoso

This is usual. The memory usage per host is (Memory required for host process + Memory required for VMs + VMs overhead)

When you install ESXI, out of total memory allocated to host, certain memory reserved for host's process including vmkernel. This will vary from one host to another based on the how much memory total ESXI host have. You can view and compare this under :

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When your'e adding host to vcenter or adding distributed switch to host, memory increase in MB is usual as vpxd agent is loaded to ESXI and distributed switch data is syncing into /etc/vmware/dvsdata.db on each host. So taking this amount of MB is considerable.

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Pille66
Contributor
Contributor

new status:

created a vSAN and added the 3 Hosts - memory up to 12 gb

its the vSAN which consumes that mamory. 10 gb for vsan ?

can somebody tell me something which is worth 10 gb

can i reduce it somehow ?

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Finikiez
Champion
Champion

First of all, you can check memory utilization with esxtop and memory screen

VSAN memory consumption is described here Understanding vSAN memory consumption in ESXi 6.5.0d/ 6.0 U3 and later (2113954) | VMware KB

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vijayrana968
Virtuoso
Virtuoso

I see, for vsan there will be much more memory requirements as this is based on disk groups youre going to configure plus considered with ssd storage you have. Please check above provided link to understand this. Also there is vsan hardware sizing calculator available for vsan on vmware site Which will give you idea how much resources require in your case.

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