Open Stack

On 05/05/2014 04:19 PM, Jiang, Yunhong wrote:
>> -----Original Message-----
>> From: Jay Pipes [mailto:jaypipes at gmail.com]
>> Sent: Monday, May 05, 2014 9:50 AM
>> To: openstack-dev at lists.openstack.org
>> Subject: Re: [openstack-dev] [nova] Question about addit log in
>> nova-compute.log
>>
>> On 05/04/2014 11:09 PM, Chen CH Ji wrote:
>>> Hi
>>>                  I saw in my compute.log has following logs which looks
>>> to me strange at first, Free resource is negative make me confused and I
>>> take a look at the existing code
>>>                  looks to me the logic is correct and calculation doesn't
>>> have problem ,but the output 'Free' is confusing
>>>
>>>                  Is this on purpose or might need to be enhanced?
>>>
>>> 2014-05-05 10:51:33.732 4992 AUDIT nova.compute.resource_tracker
>> [-]
>>> Free ram (MB): -1559
>>> 2014-05-05 10:51:33.732 4992 AUDIT nova.compute.resource_tracker
>> [-]
>>> Free disk (GB): 29
>>> 2014-05-05 10:51:33.732 4992 AUDIT nova.compute.resource_tracker
>> [-]
>>> Free VCPUS: -3
>>
>> Hi Kevin,
>>
>> I think changing "free" to "available" might make things a little more
>> clear. In the above case, it may be that your compute worker has both
>> CPU and RAM overcommit enabled.
>>
>> Best,
>> -jay
>
> HI, Jay,
> 	I don't think change 'free' to 'available' will make it clearer.
> 	IMHO, the calculation of the 'free' is bogus. When report the status in the periodic task, the resource tracker has no idea of the over-commit ration at all, thus it simply subtract the total RAM number assigned to instances from the RAM number provided by hypervisor w/o considering the over-commitment at all. So this number really have meaningless.

Agreed that in it's current state, it's meaningless. But... that said, 
the numbers *could* be used to show oversubscription percentage, and you 
don't need to know the max overcommit ratio in order to calculate that 
with the numbers already known.

Best,
-jay