RE: [Bug 1881231] Re: colo: Can not recover colo after svm failover twice

[Zhang, Chen]

Hi Ye,

Thank you for your test and report, I will try to fix this issue.

Thanks
Zhang Chen

> -----Original Message-----
> From: Qemu-devel <qemu-devel-
> bounces+chen.zhang=intel.com@nongnu.org> On Behalf Of ye.zou
> Sent: Friday, May 29, 2020 5:47 PM
> To: qemu-devel@nongnu.org
> Subject: [Bug 1881231] Re: colo: Can not recover colo after svm failover twice
> 
> In step 3 I used following commands:
> on primary vm console:
> {"execute": "drive-mirror", "arguments":{ "device": "colo-disk0", "job-id":
> "resync", "target": "nbd://169.254.66.10:9999/parent0", "mode":
> "existing","format":"raw","sync":"full"} }
> 
> // till the job ready
> { "execute": "query-block-jobs" }
> 
> {"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=169.254.66.10,file.
> port=9999,file.export=parent0,node-name=replication0'}}
> {'execute': 'x-blockdev-change', 'arguments':{'parent': 'colo-disk0', 'node':
> 'replication0' } }
> {'execute': 'migrate-set-capabilities', 'arguments': {'capabilities': [ 
> {'capability':
> 'x-colo', 'state': true } ] } }
> {'execute': 'migrate', 'arguments': {'uri': 'tcp:169.254.66.10:9998' } }
> { "execute": "migrate-set-parameters" , "arguments":{ "x-checkpoint-delay":
> 10000 } }
> 
> --
> You received this bug notification because you are a member of qemu-
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> https://bugs.launchpad.net/bugs/1881231
> 
> Title:
>   colo: Can not  recover colo after svm failover twice
> 
> Status in QEMU:
>   New
> 
> Bug description:
>   Hi Expert,
>   x-blockdev-change met some error, during testing colo
> 
>   Host os:
>   CentOS Linux release 7.6.1810 (Core)
> 
>   Reproduce steps:
>   1. create colo vm following
> https://github.com/qemu/qemu/blob/master/docs/COLO-FT.txt
>   2. kill secondary vm and remove the nbd child from the quorum to wait for
> recover
>     type those commands on primary vm console:
>     { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 
> 'child':
> 'children.1'}}
>     { 'execute': 'human-monitor-command','arguments': {'command-line':
> 'drive_del replication0'}}
>     { 'execute': 'x-colo-lost-heartbeat'}
>   3. recover colo
>   4. kill secondary vm again after recover colo and type same commands as
> step 2:
>     { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 
> 'child':
> 'children.1'}}
>     { 'execute': 'human-monitor-command','arguments': {'command-line':
> 'drive_del replication0'}}
>     { 'execute': 'x-colo-lost-heartbeat'}
>     but the first command got error
>     { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 
> 'child':
> 'children.1'}}
>   {"error": {"class": "GenericError", "desc": "Node 'colo-disk0' does not have
> child 'children.1'"}}
> 
>   according to https://www.qemu.org/docs/master/qemu-qmp-ref.html
>   Command: x-blockdev-change
>   Dynamically reconfigure the block driver state graph. It can be used to add,
> remove, insert or replace a graph node. Currently only the Quorum driver
> implements this feature to add or remove its child. This is useful to fix a
> broken quorum child.
> 
>   It seems x-blockdev-change not worked as expected.
> 
>   Thanks.
> 
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