downsizing RAM=>memory usage OK=>but what about page file

[tom.depoorter]

Hey

I've been able to extremely downsize the RAM-size of my VMs (- 50 => - 75%)
When I look the current memory usage, everything looks fine (20-30%).
I don't get alerts, so everything looks good.

I'm just wondering, if I can be sure that the VMs are performing optimally now.
For instance are they not just using more memory of the page file (and maybe working slower).
I don't know how I can analyze this.

Who can give me some advise?

Best regards

Tom

[Vitaliy S.]

Hi Tom,

What does Active Memory counter show for the VMs that you've downsized? Do you see any swapping activity on the VMware layer?

Thanks!

[tom.depoorter]

Hi Vitaliy

The Memory Active values look more or less the same.
Should an increasing or decreasing indicate something?

By swapping activity, you mean Memory Swap Rate counters?
Those were and are still all zero.

Tom

[Vitaliy S.]

If active memory is close to allocated memory, then you might need additional memory as a buffer, when the peak workload of this VM comes.

Yes, I was referring to swap rate counters, if those are close to zero, then your VM doesn't need more memory. In order to be on the safe side, I would also recommend to monitor in-guest OS activity (such as applications performance etc.), this would allow you to confirm that you have correctly sized your VMs.

[tom.depoorter]

Hey Vitaliy

I can use the memory usage counter to evaluate the need for a buffer.
Since the value is less than 50 %, this is good, no?

By monitoring in-guest OS activity you mean perfmon/resource monitor
or just if there are or no complaints from the end users
or something else?

Best regards

Tom

[Vitaliy S.]

Tom,

Yes, that should be fine. BTW, what about consumed memory counter? Do your VMs fully commit the memory you have allocated to them? Please be aware that VMs like Exchange/SQL Server will always consume the entire RAM configured to the VM.

Yes, I was referring to both in-guest OS memory/CPU usage and end-user application experience.

Thanks!

[tom.depoorter]

Hey Vitaliy

Values counter consumed memory = configured memory in vsphere client.
But the VMs are not running SQL or Exchange.
Should this be problem?

Value memory active counter is still less than half of the consumed memory for all VMs.

Its quite amazing.
I'm running:
* windows 2003 with 1,5 GB
* windows 2003 with 0,5 GB !
* windows 2008 R2 terminal server with 2 GB !

Tom

[Vitaliy S.]

No, this shouldn't be the problem. Looks like your VMs are idling (mine are always running at max RAM), as memory consumption/usage seems low. Monitor your VMs for a week and see if there are any peak loads that would require more buffer.