Re: [Qemu-devel] [PATCH v2] numa: warn if numa 'mem' option or default RAM splitting between nodes is used.

[Igor Mammedov]

On Wed, 20 Mar 2019 13:46:59 +0000
Daniel P. Berrangé <address@hidden> wrote:

> On Wed, Mar 20, 2019 at 10:32:53AM -0300, Eduardo Habkost wrote:
> > On Wed, Mar 20, 2019 at 11:51:51AM +0000, Daniel P. Berrangé wrote:  
> > > On Wed, Mar 20, 2019 at 11:26:34AM +0100, Igor Mammedov wrote:  
> > [...]  
[...]
> > If a feature is deprecated, I would expect the management stack
> > to stop using the deprecated feature by default as soon as
> > possible, not 1 year after it was deprecated.  
> 
> True, but the challenge here is that we need to stop using the
> feature in a way that isn't going to break ability to live migrate
> VMs spawned by previous versions of libvirt. 
VM should be able to start in the first place, if we disable 'mem'
on new machine, old libvirt using 'mem' won't be able to start VM
with it, it won't ever come to migration point.
(it's a clear signal to user about mis-configured host, at least
this old/new issue shouldn't happen in downstream as it ships
compatible set of packages).

[...]
> 
> Regards,
> Daniel