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On Wed, Oct 31, 2012 at 10:07 AM, Vishvananda Ishaya
<vishvananda at gmail.com> wrote:
>
> On Oct 30, 2012, at 7:01 PM, Huang Zhiteng <winston.d at gmail.com> wrote:
>
>> I'd suggest the same ratio too.  But besides memory overcommitment, I
>> suspect this issue is also related to how KVM do memory allocation (it
>> doesn't do actual allocation of the entire memory for guest when
>> booting). I've seen compute node reported more memory than it should
>> have (e.g. 4G node has two 1GB instances running but still report >3GB
>> free memory) because libvirt driver calculates free memory simply
>> based on /proc/meminfo, which doesn't reflect how many memory guests
>> are intended to use.
>
> Ah interesting, if this is true then this is a bug we should try to fix.
> I was under the impression that it allocated all of the memory unless
> you were using virtio_balloon, but I haven't verified.
I'm pretty sure about this.  Can anyone from RedHat confirm this is
how KVM works?
>
> Vish



-- 
Regards
Huang Zhiteng