Re: [Qemu-devel] [Patch v12 resend 00/10] Block replication for continuous checkpoints

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

Stefan:Ping...

What about this feature? I have worked for it about 1 year, but it is still in the
way...

On 12/02/2015 01:31 PM, Wen Congyang wrote:
> Block replication is a very important feature which is used for
> continuous checkpoints(for example: COLO).
> 
> You can get the detailed information about block replication from here:
> http://wiki.qemu.org/Features/BlockReplication
> 
> Usage:
> Please refer to docs/block-replication.txt
> 
> This patch series is based on the following patch series:
> 1. http://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg04949.html
> 2. http://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg06043.html
> 
> You can get the patch here:
> https://github.com/coloft/qemu/tree/wency/block-replication-v12
> 
> You can get the patch with framework here:
> https://github.com/coloft/qemu/tree/wency/colo_framework_v11.2
> 
> TODO:
> 1. Continuous block replication. It will be started after basic functions
>    are accepted.
> 
> Changs Log:
> V12:
> 1. Rebase to the newest codes
> 2. Use backing reference to replcace 'allow-write-backing-file'
> V11:
> 1. Reopen the backing file when starting blcok replication if it is not
>    opened in R/W mode
> 2. Unblock BLOCK_OP_TYPE_BACKUP_SOURCE and BLOCK_OP_TYPE_BACKUP_TARGET
>    when opening backing file
> 3. Block the top BDS so there is only one block job for the top BDS and
>    its backing chain.
> V10:
> 1. Use blockdev-remove-medium and blockdev-insert-medium to replace backing
>    reference.
> 2. Address the comments from Eric Blake
> V9:
> 1. Update the error messages
> 2. Rebase to the newest qemu
> 3. Split child add/delete support. These patches are sent in another patchset.
> V8:
> 1. Address Alberto Garcia's comments
> V7:
> 1. Implement adding/removing quorum child. Remove the option non-connect.
> 2. Simplify the backing refrence option according to Stefan Hajnoczi's suggestion
> V6:
> 1. Rebase to the newest qemu.
> 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 (10):
>   unblock backup operations in backing file
>   Store parent BDS in BdrvChild
>   Backup: clear all bitmap when doing block checkpoint
>   Allow creating backup jobs when opening BDS
>   docs: block replication's description
>   Add new block driver interfaces to control block replication
>   quorum: implement block driver interfaces for block replication
>   Implement new driver for block replication
>   support replication driver in blockdev-add
>   Add a new API to start/stop replication, do checkpoint to all BDSes
> 
>  block.c                    | 145 ++++++++++++
>  block/Makefile.objs        |   3 +-
>  block/backup.c             |  14 ++
>  block/quorum.c             |  78 +++++++
>  block/replication.c        | 549 +++++++++++++++++++++++++++++++++++++++++++++
>  blockjob.c                 |  11 +
>  docs/block-replication.txt | 227 +++++++++++++++++++
>  include/block/block.h      |   9 +
>  include/block/block_int.h  |  15 ++
>  include/block/blockjob.h   |  12 +
>  qapi/block-core.json       |  34 ++-
>  11 files changed, 1093 insertions(+), 4 deletions(-)
>  create mode 100644 block/replication.c
>  create mode 100644 docs/block-replication.txt
>