Re: [PATCH v8 17/17] qemu-colo.rst: Simplify the block replication setup

[Fabiano Rosas <farosas@suse.de>]

Lukas Straub <lukasstraub2@web.de> writes:

> On the primary side we don't actually need the replication
> block driver, since it only passes trough all IO.
> So simplify the setup and also use 'blockdev-add' instead of
> 'human-monitor-command'.
>
> This is how my clients use colo in production.
>
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  docs/system/qemu-colo.rst | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/docs/system/qemu-colo.rst b/docs/system/qemu-colo.rst
> index 75abbd80298df79223cb8e70064a5dc83d70f4eb..f7d3b6439cf3401a58c412634239d1a43999a10e 100644
> --- a/docs/system/qemu-colo.rst
> +++ b/docs/system/qemu-colo.rst
> @@ -240,8 +240,8 @@ Note:
>  **4.** On Primary VM's QEMU monitor, issue command::
>  
>      {"execute":"qmp_capabilities"}
> -    {"execute": "human-monitor-command", "arguments": {"command-line": "drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.2,file.port=9999,file.export=parent0,node-name=replication0"}}
> -    {"execute": "x-blockdev-change", "arguments":{"parent": "colo-disk0", "node": "replication0" } }
> +    {"execute": "blockdev-add", "arguments": {"driver": "nbd", "node-name": "nbd0", "server": {"type": "inet", "host": "127.0.0.2", "port": "9999"}, "export": "parent0", "detect-zeroes": "on"} }
> +    {"execute": "x-blockdev-change", "arguments":{"parent": "colo-disk0", "node": "nbd0" } }
>      {"execute": "migrate-set-capabilities", "arguments": {"capabilities": [ {"capability": "x-colo", "state": true } ] } }
>      {"execute": "migrate", "arguments": {"uri": "tcp:127.0.0.2:9998" } }
>  
> @@ -269,7 +269,7 @@ Primary Failover
>  The Secondary died, resume on the Primary::
>  
>      {"execute": "x-blockdev-change", "arguments":{ "parent": "colo-disk0", "child": "children.1"} }
> -    {"execute": "human-monitor-command", "arguments":{ "command-line": "drive_del replication0" } }
> +    {"execute": "blockdev-del", "arguments": {"node-name": "nbd0"} }
>      {"execute": "object-del", "arguments":{ "id": "comp0" } }
>      {"execute": "object-del", "arguments":{ "id": "iothread1" } }
>      {"execute": "object-del", "arguments":{ "id": "m0" } }
> @@ -309,8 +309,8 @@ Wait until disk is synced, then::
>      {"execute": "stop"}
>      {"execute": "block-job-cancel", "arguments":{ "device": "resync"} }
>  
> -    {"execute": "human-monitor-command", "arguments":{ "command-line": "drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.2,file.port=9999,file.export=parent0,node-name=replication0"}}
> -    {"execute": "x-blockdev-change", "arguments":{ "parent": "colo-disk0", "node": "replication0" } }
> +    {"execute": "blockdev-add", "arguments": {"driver": "nbd", "node-name": "nbd0", "server": {"type": "inet", "host": "127.0.0.2", "port": "9999"}, "export": "parent0", "detect-zeroes": "on"} }
> +    {"execute": "x-blockdev-change", "arguments":{ "parent": "colo-disk0", "node": "nbd0" } }
>  
>      {"execute": "object-add", "arguments":{ "qom-type": "filter-mirror", "id": "m0", "netdev": "hn0", "queue": "tx", "outdev": "mirror0" } }
>      {"execute": "object-add", "arguments":{ "qom-type": "filter-redirector", "id": "redire0", "netdev": "hn0", "queue": "rx", "indev": "compare_out" } }
> @@ -341,8 +341,8 @@ Wait until disk is synced, then::
>      {"execute": "stop"}
>      {"execute": "block-job-cancel", "arguments":{ "device": "resync" } }
>  
> -    {"execute": "human-monitor-command", "arguments":{ "command-line": "drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,file.port=9999,file.export=parent0,node-name=replication0"}}
> -    {"execute": "x-blockdev-change", "arguments":{ "parent": "colo-disk0", "node": "replication0" } }
> +    {"execute": "blockdev-add", "arguments": {"driver": "nbd", "node-name": "nbd0", "server": {"type": "inet", "host": "127.0.0.1", "port": "9999"}, "export": "parent0", "detect-zeroes": "on"} }
> +    {"execute": "x-blockdev-change", "arguments":{ "parent": "colo-disk0", "node": "nbd0" } }
>  
>      {"execute": "object-add", "arguments":{ "qom-type": "filter-mirror", "id": "m0", "insert": "before", "position": "id=rew0", "netdev": "hn0", "queue": "tx", "outdev": "mirror0" } }
>      {"execute": "object-add", "arguments":{ "qom-type": "filter-redirector", "id": "redire0", "insert": "before", "position": "id=rew0", "netdev": "hn0", "queue": "rx", "indev": "compare_out" } }

Reviewed-by: Fabiano Rosas <farosas@suse.de>