Question on VMWare VM Host Memory

[TonyJK]

Hi,

I find that the VMWare assigned Host Memory is of similar size as assigned Guest Memory (Like: If we allocate 8GB to that VM, Host Memory allocated is also 8GB).

From the following blog, I also under the relationship between "VMware Consumed Host Memory vs Active Guest Memory"

https://www.virtualmvp.com/vmware-consumed-host-memory-vs-active-guest-memory/

May I ask if we only have limited RAM on ESXi Hosts (i.e. Total amount of memory allocated to VM > RAM on ESXi Host in Cluster), what will be the Host Memory assigned and is there any mechanism for ESXi Host to reclaim Memory ?

Thanks

[HassanAlKak88 · Accepted solution]

Hello,

I guess the following will more explains for your the confused point: Memory Overcommitment

[depping]

Yes. ESXi has multiple mechanisms to reclaim memory:

• TPS aka transparent page sharing --> share pages between guests (disabled by default these days for security reasons)
• Ballooning
• Compress pages
• Paging / Swap to disk

There's a whole bunch of articles to be found on google on this topic, but easiest is to read chapter 6 from this pdf:

https://docs.vmware.com/en/VMware-vSphere/6.5/vsphere-esxi-vcenter-server-65-resource-management-gui...