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Re: [Qemu-devel] [PATCH v4 00/18] bitmaps: introduce 'bitmap' sync mode
From: |
Fabian Grünbichler |
Subject: |
Re: [Qemu-devel] [PATCH v4 00/18] bitmaps: introduce 'bitmap' sync mode |
Date: |
Mon, 22 Jul 2019 14:17:55 +0200 |
User-agent: |
NeoMutt/20180716 |
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.
- [Qemu-devel] [PATCH v4 05/18] block/backup: Add mirror sync mode 'bitmap', (continued)
- [Qemu-devel] [PATCH v4 05/18] block/backup: Add mirror sync mode 'bitmap', John Snow, 2019/07/09
- [Qemu-devel] [PATCH v4 09/18] block/dirty-bitmap: add bdrv_dirty_bitmap_merge_internal, John Snow, 2019/07/09
- [Qemu-devel] [PATCH v4 18/18] block/backup: loosen restriction on readonly bitmaps, John Snow, 2019/07/09
- [Qemu-devel] [PATCH v4 17/18] iotests: add test 257 for bitmap-mode backups, John Snow, 2019/07/09
- Re: [Qemu-devel] [PATCH v4 00/18] bitmaps: introduce 'bitmap' sync mode, Max Reitz, 2019/07/10
- Re: [Qemu-devel] [PATCH v4 00/18] bitmaps: introduce 'bitmap' sync mode, John Snow, 2019/07/15
- Re: [Qemu-devel] [PATCH v4 00/18] bitmaps: introduce 'bitmap' sync mode,
Fabian Grünbichler <=