Re: [Qemu-devel] [RFC PATCH 0/2] live backup vm

[Dietmar Maurer]

> > So our snapshot implementation uses the following steps:
> >
> > 1.) qmp: savevm-start [statefile]
> >
> > This save the VM state into [statefile] and then stops the VM.
> 
> That's migrate exec:cat>statefile (or similar)

We save to block devices, so we need to allocate them in advance
with a size of 2 x 'memory size'.
So we have an upper limit for the state file file, i.e. we stop the
VM if ('statefile size' > 'assigned memory').

It would be great to have some other means to reduce state size (instead 
of stopping the VM), for example by slowing down the VM somehow? 
Any other ideas?