Re: [Qemu-devel] [patch 4/4] QEMU live block copy

[Jiri Denemark <jdenemar@redhat.com>]

On Wed, Jun 15, 2011 at 14:14:07 -0300, Marcelo Tosatti wrote:
> Index: qemu-block-copy/qmp-commands.hx
> ===================================================================
> --- qemu-block-copy.orig/qmp-commands.hx
> +++ qemu-block-copy/qmp-commands.hx
...
>  SQMP
> +query-block-copy
> +-------------
> +
> +Live block copy status.
> +
> +Each block copy instance information is stored in a json-object and the returned
> +value is a json-array of all instances.
> +
> +Each json-object contains the following:
> +
> +- "device": device name (json-string)
> +- "status": block copy status (json-string)
> +    - Possible values: "active", "failed", "mirrored", "completed", meaning:
> +                    - failed: block copy failed.
> +                    - stopped: block copy stopped.
> +                    - active: block copy active, copying to destination image.
> +                    - mirrored: block copy active, finished copying to destination
> +                      image, writes are mirrored.
> +                    - completed: block copy completed.
> +
> +- "info": A json-object with the statistics information, if status is "active":
> +    - "percentage": percentage completed (json-int)
> +
> +Example:
> +
> +Block copy for "ide1-hd0" active and block copy for "ide1-hd1" failed:
> +
> +-> { "execute": "query-block-copy" }
> +<- {
> +      "return":[
> +        {"device":"ide1-hd0",
> +            "status":"active",
> +            "info":{
> +               "percentage":23,
> +            }
> +        },
> +        {"device":"ide1-hd1",
> +         "status":"failed"
> +        }
> +      ]
> +   }
> +
> +EQMP

This documentation doesn't reflect the changes to progress reporting you made
in the code.

> Index: qemu-block-copy/docs/block_copy.txt
> ===================================================================
> --- /dev/null
> +++ qemu-block-copy/docs/block_copy.txt
...
> +Migration
> +=========
> +
> +It is necessary to specify active block copy instance in the destination
> +VM before migration is performed. Example:
> +
> +1) start VM in incoming mode.
> +2) for each active block copy instance on the source, run:
> +    (qemu) block_copy device /path/to/image.dst [-i] -m
> +
> +

I guess I'm a bit behind but what exactly can this migration support in
block_copy be used for?

Jirka