Re: [PATCH 2/4] migration: Add block-bitmap-mapping parameter

[Vladimir Sementsov-Ogievskiy]

02.07.2020 12:41, Max Reitz wrote:
> > > > As I've said before, it may be reasonable to ignore bitmaps not
> > > > referenced in the hash-table.
> > > No problem with that.  We just decided on this behavior when we
> > > discussed the RFC.
> > Sorry for that. The reason for my changed opinion is a recent bug from
> > customers about bitmap migration.
> No problem.  (My original proposal was different still, where
> non-specified mappings would default to the identity mapping.)

And, remembering, what my series "[PATCH v2 00/22] Fix error handling during bitmap 
postcopy" is for, I have one more reason for non-strict behavior around bitmap 
migration in general:

Bitmaps are migrating postcopy. We can't rollback in general, so we should 
ignore any error during bitmaps migration, as it's non critical data, and we 
must not break already running target due to some bitmap issue. Failed bitmap 
migration should never be a problem, the worst consequence is necessity to 
create a full backup instead of incremental.


--
Best regards,
Vladimir