VM vSphere CPU Resource set to Unlimited by vCD

[seizadi]

I have been trying to chase down why vCD is setting the CPU Resource of the VM to Unlimited when it powers on the VM. If I  edit the setting from vSphere Client and change it so that it is not set and power it from vSphere it works fine. If I power it on from vCD it overrides the setting and set it to Unlimited. So where is this setting for the VM configured in vCD and how can I override it? I attached the screenshot from vSphere showing the resource set by vCD.

Thanks,

-Soheil

[cfor]

This is based on your OrgVDC settings.  I think the default is unlimited CPU reservation (shows as 0%) - if you want a reservation to be set you have to set the OrgVDC to set this.  When a VM is powered on these settings are rewritten.

[seizadi]

The setting of the OrgvDC should drive the backing vSphere Cluster properties. I have checked it and it is not set to Unlimited CPU resources. The CPU reservation was not set to 0% for this OrgvDC. I have changed it to 0% and 100% and it does not change this behavior. Just to be clear the setting of Unlimited is not with the Cluster properties but with the individual VM that gets run. Also when I look at the VM Properities when it is first created it is not set to Unlimited. If I manually run it from vSphere Client then it starts fine w/o Unlimited CPU, but when I start it using vCD GUI I get the behavior of having the CPU set to Unlimited. Also when I stop the instance from vCD the VM properties is now set to Unlimited, so the change is permenant.

[seizadi]

Found the root cause of this problem ....

There are three allocation models in vCD: 1). Allocation Pool, 2). Pay As You Go and 3). Reservation Pool.

If you select Allocation Pool, vCD will create all VM instances in that Cluster with CPU Unlimited.

Created a new Pay As You Go OrgVDC and got the desired behavior of leaving the VM setting as they were in the original template.

Two questions remain:

- How you select Allocation Pool but not have the CPU property set to Unlimited?

- How to change the allocation model after the OrgVDC is created?

At least for now I have a work around, that works for my use case.

-Soheil

[CharlieLlewelly]

Hi Seizadi,

This is the same we found. Under the allocation model the CPU is always unlimted (no idea why although this has actually helped us) but memory does honour the reservation?? I have found no way to change this with vCD only in vSphere which is not recommended.

Finally there is no way to change the model on a OvDC you will need to create a new and migrate your services into that.

Cheers Charlie

[viktorious]

Hi,

I would advice to read this article by Duncan Epping:

http://www.yellow-bricks.com/2010/09/22/vcd-allocation-models/

The article explains how resource settings work related to the three alocations models. Each model has it own characteristics for the Resource Pool en VM resource settings. For the model "allocation pool" the following rules count for VM's:

VM Level characteristics

• No reservations or limits set on a per VM level for CPU
• Reservations set on a per VM level for memory. This reservation is based on the percentage of guaranteed resources

So, I don't think you can select allocation pool without the CPU property set to unlimited, and changing an allocation model after creating the Org vDC is not possible (as fas as I know). The allocation model is linked to the org vDC because is determines the level guarantee for the resources....

Hope this helps a bit...!