Re: Balloon driver.

["Cherry G. Mathew" <cherry.g.mathew%gmail.com@localhost>]

On 7 July 2010 13:37, Stephen Borrill <netbsd%precedence.co.uk@localhost> wrote:
> On Tue, 6 Jul 2010, Cherry G. Mathew wrote:
>>
>> Briefly, there are two methods to play with this now.
>>
>>> From dom0:
>>
>> # xm mem-set $domid $newmemsz
>>
>> or, from within the domU
>>
>> # sysctl -w kern.xen.balloon.target=$newtargetinpages
>
> How would you stop the domU being able to increase its memory size (e.g. on
> a hosted service, you wouldn't want the client taking more resources than
> they've paid for)?
>

There are no such limits by design at the moment. However at the
moment a de-facto limit exists (ie; the amount specified in the domU
config file), because we don't add more pages than we had to begin
with. Fixing this will need looking at uvm(9).)

In any case, I'm not sure this kind of policy should be set from
within the VM kernel. IMHO, the correct approach would be for the
hypervisor to follow policy per VM similar to dom0-min-mem

Cheers,

-- 
~Cherry