On 05.07.19 22:16, John Snow wrote:
> This adds an "always" policy for bitmap synchronization. Regardless of if
> the job succeeds or fails, the bitmap is *always* synchronized. This means
> that for backups that fail part-way through, the bitmap retains a record of
> which sectors need to be copied out to accomplish a new backup using the
> old, partial result.
> 
> In effect, this allows us to "resume" a failed backup; however the new backup
> will be from the new point in time, so it isn't a "resume" as much as it is
> an "incremental retry." This can be useful in the case of extremely large
> backups that fail considerably through the operation and we'd like to not waste
> the work that was already performed.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  block/backup.c       | 27 +++++++++++++++++++--------
>  qapi/block-core.json |  5 ++++-
>  2 files changed, 23 insertions(+), 9 deletions(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>