On 04/18/2018 10:00 AM, Vladimir Sementsov-Ogievskiy wrote: > Hi all. > > We now have the following problem: > > If dirty-bitmaps migration capability is enabled, persistance flag is > dropped for all migrated bitmaps, to prevent their storing to the > storage on inactivate. It works ok, persistence itself is migrated > through the migration channel. But on source, bitmaps becomes not > persistent, so if we, for some reasons, want to continue using source > vm, we'll lose bitmaps on stop/start. >
Sorry for not following along more carefully, which kind of migration are we talking about in this case? > It's simple to fix it: just make bitmaps persistent again on invalidate > [1].. But I have some questions. > > 1. What are possible cases? I think about the following: > > a. migration cancel or fail, then invalidate > b. migration success, then qmp cont => invalidate > c. migration success, then stop/start (there was no invalidate, so [1] > will not work) > > > 2. Is it safe at all, saving bitmaps after inactivate, even without > persistence? > > Inactive disk implies, that it may be changed by somebody other, isn't > it? Is it possible, that target will change the disk, and then we return > control to the source? In this case bitmaps will be invalid. So, should > not we drop all the bitmaps on inactivate? >
