hi,
>At the moment in your implementation the prefetch buffer can be very large (several copies of guest memory size)
>are you planning to address this issue?
>I agree but we need some way to notify the user of such problem.
This issue has been handled (maybe not in the best way). The prefetch buffer size could be increased up to 1.5 * vm memory size. When the migration data size is larger than it, the prefetching is stopped with a warning (pls refer to the code 4/4) and the loading is started. In this situation, broken-in-the-middle problem is inevitable.
>>>The second is that sadly live migration doesn't always converge this means >that the backup VM won't have a consist state to failover to. >You need to detect such a case and throttle down the guest to force convergence.
>
>> Yes, that's a problem. AFAK, qemu already have an auto convergence feature.
> How about activating it when you do fault tolerance automatically?
That is feasible. Any comments by others?