[Lxc-users] Copy-on-write hard-link / hashify feature

[Daniel Lezcano]

On 06/11/2010 11:08 AM, Gordan Bobic wrote:
> On 06/11/2010 09:57 AM, Daniel Lezcano wrote:
>> On 06/10/2010 10:54 PM, Gordon Henderson wrote:
>>> On Thu, 10 Jun 2010, John Drescher wrote:
>>>
>>>
>>>> BTW, a second option is lessfs.
>>>>
>>>> http://www.lessfs.com/wordpress/?page_id=50
>>>>
>>> What about the KSM kernel option? It's aimed at KVM I think and in the
>>> kernel from 2.6.32. See:
>>>
>>>      http://lwn.net/Articles/306704/
>>> and
>>>      http://lwn.net/Articles/330589/
>>>
>>> Not sure if that could be used to help here - it seems a bit of a
>>> retrospective way to find data duplications - assuming we could enable it
>>> for whole containers...
>>>
>>
>> KSM is enabled on my ubuntu 10.04. When I do a compilation, ksm takes
>> more cpu than the compilation itself and is always eating 10-30% of my
>> cpu (Intel(R) Core(TM)2 Duo CPU T9500  @ 2.60GHz). So I disabled it
>> definitively ...
>
> Are you saying that KSM is performing memory de-duplication on bare
> metal, rather than inside a KVM VM? That can't be right.
>
> My guess that you have it misconfigured to be scanning the memory too
> frequently and it's spinning empty?

Yes, I think it is probable. I didn't tune the ubuntu default settings.