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From Wido den Hollander <w...@widodh.nl>
Subject Re: KVM Max Guests Limit
Date Fri, 09 Nov 2018 12:03:22 GMT


On 11/9/18 12:56 PM, Andrija Panic wrote:
> afaik not - but I did run once or twice intom perhaps looselym connected
> issue - ACS reports 100% of host RAM (makes sense) asavailable for VM
> deployment to ACS - so in 1-2 cases I did run into out of memory killer,
> crashing my VMs.
> 
> It would be great to have some amount of "reserve RAM" for host OS - or
> simply have PER HOST RAM disableTreshold setting, similar to cluster level
> "cluster.memory.allocated.capacity.disablethreshold", just on host level...
> 


You can do that already, in agent.properties you can set reserved memory.

But I doubt indeed that we need such a limit in ACS at all, why do we
need to limit the amount of Instances on a hypervisor?

Or at least set it to a very high number by default.

Wido

> On Fri, 9 Nov 2018 at 12:03, Rafael Weingärtner <rafaelweingartner@gmail.com>
> wrote:
> 
>> Do we need these logical constraints in ACS at all?
>>
>> On Fri, Nov 9, 2018 at 6:57 AM Wido den Hollander <wido@widodh.nl> wrote:
>>
>>>
>>>
>>> On 11/8/18 11:20 PM, Simon Weller wrote:
>>>> I think these is legacy and a guess back in the day. It was 50 at one
>>> point and it was lifted higher a few releases. ago.
>>>>
>>>
>>> I see. I'm about to do a test with a bunch of 128GB hypervisors and
>>> spawning a lot of 128M VMs. Trying to see where the limit might be and
>>> also stress the VR a bit by loading a lot of DHCP entries.
>>>
>>> Wido
>>>
>>>>
>>>>
>>>>
>>>> ________________________________
>>>> From: Ivan Kudryavtsev <kudryavtsev_ia@bw-sw.com>
>>>> Sent: Thursday, November 8, 2018 3:58 PM
>>>> To: dev
>>>> Subject: Re: KVM Max Guests Limit
>>>>
>>>> Hi all, +1 for higher numbers.
>>>>
>>>> чт, 8 нояб. 2018 г. в 16:32, Wido den Hollander <wido@widodh.nl>:
>>>>
>>>>> Hi,
>>>>>
>>>>> I see that for KVM we set the limit to 144 guests by default, can
>>>>> anybody tell me why we have this limit set to 144?
>>>>>
>>>>> Searching a bit I found this:
>>>>> https://access.redhat.com/articles/rhel-kvm-limits
>>>>>
>>>>> "This guest limit does not apply to Red Hat Enterprise Linux with
>>>>> Unlimited Guests. There is no guest limit for Red Hat Enterprise
>>>>> Virtualization"
>>>>>
>>>>> There is always a limit somewhere, but why do we set it to 144?
>>>>>
>>>>> I would personally vote for increasing this to 500 or something so
>> that
>>>>> users don't run into it that easily.
>>>>>
>>>>> Also, the log line is printed in DEBUG mode only when a host reaches
>>>>> this limit, so I created a PR to set this to INFO:
>>>>> https://github.com/apache/cloudstack/pull/3013
>>>>>
>>>>> Any input?
>>>>>
>>>>> Wido
>>>>>
>>>>
>>>>
>>>> --
>>>> With best regards, Ivan Kudryavtsev
>>>> Bitworks LLC
>>>> Cell RU: +7-923-414-1515
>>>> Cell USA: +1-201-257-1512
>>>> WWW: http://bitworks.software/ <http://bw-sw.com/>
>>>>
>>>
>>
>>
>> --
>> Rafael Weingärtner
>>
> 
> 

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