Re: [Qemu-devel] question about live migration with storage

[Zhang Haoyu]

On 2015-01-14 15:42:41, Paolo Bonzini wrote:
> 
> On 14/01/2015 03:41, Zhang Haoyu wrote:
> > Hi, Paolo,
> > what's advantages of drive_mirror over traditional mechanism implemented in 
> > block-migration.c ?
> > Why libvirt use drive_mirror instead of traditional iterative mechanism as 
> > the default way
> > of live migration with non-shared storage?
> 
> 1) Being able to choose which block devices are migrated, and whether
> they are migrated incrementally or not.
> 
Yes.
> 2) Finer-grain control the parameters of block migration (dirty bitmap
> granularity).
> 
> 3) Block and RAM migration do not share the same socket and thus can
> more easily be parallelized.
> 
But, because of the parallelization, how to calculate the progress?

BTW, the traditional iterative mechanism is buggy-implemented?
e.g., some bugs which are very difficult to fixed, or something?

Thanks,
Zhang Haoyu
> Note that 1-2 are not yet supported by libvirt as far as I remember.
> 
> Paolo