On Tue, Jul 09, 2019 at 07:25:32PM -0400, John Snow wrote: > This series adds a new "BITMAP" sync mode that is meant to replace the > existing "INCREMENTAL" sync mode. > > This mode can have its behavior modified by issuing any of three bitmap sync > modes, passed as arguments to the job. > > The three bitmap sync modes are: > - ON-SUCCESS: This is an alias for the old incremental mode. The bitmap is > conditionally synchronized based on the return code of the job > upon completion. > - NEVER: This is, effectively, the differential backup mode. It never clears > the bitmap, as the name suggests. > - ALWAYS: Here is the new, exciting thing. The bitmap is always synchronized, > even on failure. On success, this is identical to incremental, but > on failure it clears only the bits that were copied successfully. > This can be used to "resume" incremental backups from later points > in times. > > I wrote this series by accident on my way to implement incremental mode > for mirror, but this happened first -- the problem is that Mirror mode > uses its existing modes in a very particular way; and this was the best > way to add bitmap support into the mirror job properly. > > [...] > > Future work: > [..] > - Add these modes to Mirror. (Done*, but needs tests.)
are these mirror patches available somehwere for testing in combination with this series? your bitmaps branch does not seem to contain them ;) we've been experimenting with Ma Haocong's patch (v4 from February) to add "incremental"/differential sync to drive-mirror recently with positive results so far, and this sounds like it is another attempt at getting this properly integrated into Qemu.
