[pve-devel] pve-manager : expose balloon to gui

[Dietmar Maurer]

> So maybe using free_mem counter is enough ?
> (We should of course check the swap to see if the kernel is not swapping to
> keep free mem)
> 
> 
> But yes, having buffer stats could help a lot.

I guess we need buffer stats do work effectively. And worse, it seems
the windows driver does not return any stats.

> Note that citrix xenserver is using only the min_balloon size defined in vm
> config, it should be tunned to be enough big to not crash the guest if memory
> is reduced.
> (in worst case you should have enough swap in guest to handle the memory
> reduce)

we want to be better than that ;-)
 
> >>So maybe it is faster to work on the guest-agent infrastructure
> >>instead. I guess it is much easier to modify the user space tools than a
> kernel driver.
> 
> Yes, I think we could implement qemu-ga for this. Easy for linux (get free
> command result), not sure for windows guest(lauching some scripts ?).
> I don't have too much time to work on qemu-ga (multiplexing give me
> headache ;).
> Can you work on this ? (my old patches works but need to be polished)

Yes, I will try to get that work.
 
> >>Note: fixing the kernel driver is quite easy, but I doubt we can force
> >>all distrib. to apply/backport those patches.
> Yes, I don't think distro will backport,I'll just be include in new kernel version.
> So it can take time.
> 
> 
> >>They also talk about a kernel-based auto-ballooning feature! I requested
> more
> >>information about that.
> Never heart about this. But it can take time to be ready (years ?)

Yes ;-) So lets try the guest-agent (we need that anyways).