Re: [Qemu-devel] [PATCH v2 2/3] block: add block-backup QMP command

[Kevin Wolf]

Am 29.04.2013 um 09:42 hat Stefan Hajnoczi geschrieben:
> @block-backup
> 
> Start a point-in-time copy of a block device to a new destination.  The
> status of ongoing block backup operations can be checked with
> query-block-jobs.  The operation can be stopped before it has completed using
> the block-job-cancel command.
> 
> @device: the name of the device whose writes should be mirrored.
> 
> @target: the target of the new image. If the file exists, or if it
>          is a device, the existing file/device will be used as the new
>          destination.  If it does not exist, a new file will be created.
> 
> @format: #optional the format of the new destination, default is to
>          probe if @mode is 'existing', else the format of the source
> 
> @mode: #optional whether and how QEMU should create a new image, default is
>        'absolute-paths'.
> 
> @speed: #optional the maximum speed, in bytes per second
> 
> Returns: nothing on success
>          If @device is not a valid block device, DeviceNotFound
> 
> Since 1.6
> 
> Signed-off-by: Stefan Hajnoczi <address@hidden>

drive-backup would probably be a more consistent naming. We would then
still have block-backup for a future low-level command that doesn't
create everything by itself but takes an existing BlockDriverState (e.g.
created by blockdev-add).

We should also make it transactionable from the beginning, as we don't
have schema introspection yet. This way we allow to assume that if the
standalone command exists, the transaction subcommand exists as well.

Kevin