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

[Alexandre DERUMIER]

>>The MOM Ballooning Policy does not look very complex. But if we can't implement it 
>>inside qemu, we can still use pvestatd. 

>>But we first need to know if/how we can get stats from the guest? 

If we want to reduce memory 100% safely, I think we need to get stats.
But balloon stats seem to give "free_memory", without memory used as buffer in guest. 
(And as Linux try to use all free memory for buffer, I'm not sure that free_memory will be huge)

I we want to add memory, I can be done if host have enough memory.

Another way (that citrix xenserver use) it to specify manually a range (min-max) for balloon memory (which is safe for the workload of the vm).
Then the daemon (pvestatd), can adjust balloon in this range.




----- Mail original ----- 

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Jeudi 6 Décembre 2012 08:56:26 
Objet: RE: [pve-devel] pve-manager : expose balloon to gui 

> >>But for me this only makes sense if we do not need a daemon inside the 
> >>guest, and qemu can handle ballooning itself (no 'momd'). 
> 
> I'm not a big fan of automatic memory management (because it's a complex 
> thing), but why not. 
> I'm not sure a single qemu process can manage it easily, because it need to 
> known if you can reclaim space from another qemu,or if host have enough 
> memory free. 

The MOM Ballooning Policy does not look very complex. But if we can't implement it 
inside qemu, we can still use pvestatd. 

But we first need to know if/how we can get stats from the guest?