Re: [Qemu-devel] [PATCH COLO-Block v5 00/15] Block replication for continuous checkpoints

[Wen Congyang <wency@cn.fujitsu.com>]

On 05/21/2015 12:52 PM, Wen Congyang wrote:
> Block replication is a very important feature which is used for
> continuous checkpoints(for example: COLO).
> 
> Usage:
> Please refer to docs/block-replication.txt
> 
> You can get the patch here:
> https://github.com/wencongyang/qemu-colo/commits/block-replication-v5
> 
> The other newest COLO patchse will be sent soon.
> 
> TODO:
> 1. Continuous block replication. It will be started after basic functions
>    are accepted.

I forgot to methin that: you should apply the following patch first:
http://lists.nongnu.org/archive/html/qemu-devel/2015-05/msg01317.html

Thanks
Wen Congyang

> 
> Changs Log:
> V5:
> 1. Address the comments from Gong Lei
> 2. Speed the failover up. The secondary vm can take over very quickly even
>    if there are too many I/O requests.
> V4:
> 1. Introduce a new driver replication to avoid touch nbd and qcow2.
> V3:
> 1: use error_setg() instead of error_set()
> 2. Add a new block job API
> 3. Active disk, hidden disk and nbd target uses the same AioContext
> 4. Add a testcase to test new hbitmap API
> V2:
> 1. Redesign the secondary qemu(use image-fleecing)
> 2. Use Error objects to return error message
> 3. Address the comments from Max Reitz and Eric Blake
> Wen Congyang (15):
>   docs: block replication's description
>   allow writing to the backing file
>   Allow creating backup jobs when opening BDS
>   block: Parse "backing_reference" option to reference existing BDS
>   Backup: clear all bitmap when doing block checkpoint
>   Don't allow a disk use backing reference target
>   Add new block driver interface to connect/disconnect the remote target
>   NBD client: implement block driver interfaces to connect/disconnect
>     NBD server
>   Introduce a new -drive option to control whether to connect to remote
>     target
>   NBD client: connect to nbd server later
>   Add new block driver interfaces to control block replication
>   skip nbd_target when starting block replication
>   quorum: implement block driver interfaces for block replication
>   quorum: allow ignoring child errors
>   Implement new driver for block replication
> 
>  block.c                    | 272 +++++++++++++++++++++++++++-
>  block/Makefile.objs        |   3 +-
>  block/backup.c             |  13 ++
>  block/nbd.c                |  69 +++++--
>  block/quorum.c             | 142 ++++++++++++++-
>  block/replication.c        | 441 +++++++++++++++++++++++++++++++++++++++++++++
>  blockdev.c                 |   8 +
>  blockjob.c                 |  10 +
>  docs/block-replication.txt | 179 ++++++++++++++++++
>  include/block/block.h      |  10 +
>  include/block/block_int.h  |  18 ++
>  include/block/blockjob.h   |  12 ++
>  qapi/block.json            |  16 ++
>  qemu-options.hx            |   4 +
>  tests/qemu-iotests/051     |  13 ++
>  tests/qemu-iotests/051.out |  13 ++
>  16 files changed, 1193 insertions(+), 30 deletions(-)
>  create mode 100644 block/replication.c
>  create mode 100644 docs/block-replication.txt
>