On 9/10/22 09:35, liuhaiwei wrote:
From: liuhaiwei <liuhai...@inspur.com>
bug description as https://gitlab.com/qemu-project/qemu/-/issues/1203
Usually,we use the precopy or postcopy mode to migrate block dirty bitmap.
but if block-dirty-bitmap size more than threshold size,we cannot entry the
migration_completion in migration_iteration_run function
To solve this problem, we can setting the pending size to a fake
value(threshold-1 or 0) to tell migration_iteration_run function to entry the
migration_completion,if pending size > threshold size
Actually, bitmaps migrate in postcopy. So, you should start postcopy for it to work (qmp
command migrate-start-postcopy). This command simply set the boolean variable, so that in
migration_iteration_run() we'll move to postcopy when needed. So, you can start this
command immediately after migrate command, or even before it, but after setting the
"dirty-bitmaps" capability.
Fake pending is a wrong thing to do, it means that you will make downtime to be
larger than expected.
--
Best regards,
Vladimir
