Consumed Memory

[pramodnaik]

For a Virtual Machine, Consumed Memory is the physical memory 'touched' by  the VM.

During idle conditions, no hot ESXi and no memory pressure:

Does the consumed memory go down? this counter should always increase, is that correct?  will the VM ever release its consumed memory?

the only way to recover the consumed memory use by the VM is to reboot the VM and start fresh.

off course, when the Hosts is running hot on memory and starts using using Ballooning and swamping to release consumed memory. But my question above is related to idle conditions.

thanks

[vijayrana968]

Consumed memory should be little greater than active one, this is the highest % of memory VM has used in past. If it goes down, it means there something not good with memory allocation.

Please refer to Page 15-16 on https://www.metron-athene.com/documents/papers/taking-a-trip-down-vSphere-memory-lane.pdf

[Sreejesh_D]

hi,

For a Virtual Machine, Consumed Memory is the physical memory 'touched' by  the VM.

>>>> a correction in the above statement. The above description is for the Active memory.

Active Memory – “Amount of memory that is actively used, as estimated by VMkernel based on recently touched memory pages.”

Consumed memory and Active memory have different definitions at VM and Host level.

The best resource would be the following article from VMware. It clearly explain and define each counters at VM and Host level.

Memory Counters

Does the consumed memory go down? this counter should always increase, is that correct?  will the VM ever release its consumed memory?

>>> As mentioned in the above article at host level "consumed memory = total host memory - free host memory ". So whatever happens at the host level which will increase the free memory will increase consumed memory. For example, Power off a VM, VMotion a VM out of the host, uninstall some agents at host level which consume host memory, etc.

[pramodnaik]

thanks for the reply.

my question is specific to Virtual machine - consumed memory. When a VM powers on, ESXi starts providing memory to the virtual machine. this is addition to the overhead. See snapshot attached.

Now, this consumed memory is the actual memory assigned to the VM and will be used for capacity planning purposes.

the question is: does this consumed memory ever do down.  Meaning, is there a possibility where the guest release memory during the period of inactivity. i know about the ballooning and other ways the host initiates to recover memory. But, does at any time the guest itself release the memory by itself, say when its idle.

thanks