[Lguest] Help on ballooning for lguest

[iggy at theiggy.com]

On Friday 12 March 2010 04:18:02 Gaurav Kukreja wrote:
> Hi,
> 
> I am working to enable ballooning support for lguest.
> 
> Please care to correct me, if I am wrong.
> 
> I have read very little about ballooning in Xen, and have found out, they
> use a userspace script in the host. This script reads statistics posted by
> each of the guests in Xenstore, which is a posting area that is shared by
> the guests and the host. The userspace script, that is called
> self-ballooning, then decides how much memory from whom to take and whom to
> give.

KVM doesn't have anything like that at this point. It's all still manual (some 
management frameworks may have support). You can access the statistics via 
QEMU/KVM's monitor.

> 
> Now, for lguest, i present my idea. I want to make a userspace program,
> that will be used to configure and launch the guest. This userspace
> program will also maintain, a series of statistics delivered by each of
> the guest, maybe through a virtio device driver, in a Xenstore like area.
> The same userspace program will continuously evaluate the statistics, and
> decide how much to balloon, much like the self-ballooning script in Xen.

There's already a virtio-balloon driver that supports getting statistics from 
the guest.


> 
> Please post your ideas or suggestions on this topic. I am on a tight
> schedule, and need to get this to work very soon.