Open Stack

Ok Jay,
let me to describe my environment.
I have an openstack made up of 3 controllers nodes ad several compute nodes.
The controller nodes services are controlled by pacemaker and the compute
nodes services are controlled by remote pacemaker.
My hardware is Dell so I am using ipmi fencing device .
I wrote a service controlled by pacemaker:
this service controls if a compude node fails and for avoiding split brains
if a compute node does nod respond on the management network and on storage
network the stonith poweroff the node and then execute a nova host-evacuate.

Anycase to have a simulation before writing the service I described above
you can do as follows:

connect on one compute node where some virtual machines are running
run the command: echo 'c' > /proc/sysrq-trigger (it stops immediately the
node like in case of failure)
On a controller node run:  nova host-evacuate "name of failed compute node"
Instances running on the failed compute node should be restarted on another
compute node


Ignazio

Il giorno gio 11 lug 2019 alle ore 11:57 Jay See <jayachander.it at gmail.com>
ha scritto:

> Hi ,
>
> I have tried on a failed compute node which is in power off state now.
> I have tried on a running compute node, no errors. But nothing happens.
> On running compute node - Disabled the compute service and tried migration
> also.
>
> May be I might have not followed proper steps. Just wanted to know the
> steps you have followed. Otherwise, I was planning to manual migration also
> if possible.
> ~Jay.
>
> On Thu, Jul 11, 2019 at 11:52 AM Ignazio Cassano <ignaziocassano at gmail.com>
> wrote:
>
>> Hi Jay,
>> would you like to evacuate a failed compute node or evacuate a running
>> compute node ?
>>
>> Ignazio
>>
>> Il giorno gio 11 lug 2019 alle ore 11:48 Jay See <
>> jayachander.it at gmail.com> ha scritto:
>>
>>> Hi Ignazio,
>>>
>>> I am trying to evacuate the compute host on older version (mitaka).
>>> Could please share the process you followed. I am not able to succeed
>>> with openstack live-migration fails with error message (this is known issue
>>> in older versions) and nova live-ligration - nothing happens even after
>>> initiating VM migration. It is almost 4 days.
>>>
>>> ~Jay.
>>>
>>> On Thu, Jul 11, 2019 at 11:31 AM Ignazio Cassano <
>>> ignaziocassano at gmail.com> wrote:
>>>
>>>> I am sorry.
>>>> For simulating an host crash I used a wrong procedure.
>>>> Using  "echo 'c' > /proc/sysrq-trigger" all work fine
>>>>
>>>> Il giorno gio 11 lug 2019 alle ore 11:01 Ignazio Cassano <
>>>> ignaziocassano at gmail.com> ha scritto:
>>>>
>>>>> Hello All,
>>>>> on ocata when I  poweroff a node with active instance , doing a nova
>>>>> host-evacuate works  fine
>>>>> and instances are restartd on an active node.
>>>>> On queens it does non evacuate instances but nova-api reports for each
>>>>> instance the following:
>>>>>
>>>>> 2019-07-11 10:19:54.745 13811 INFO nova.api.openstack.wsgi
>>>>> [req-daad0a7d-87ce-41bf-b096-a70fc306db5c 0c7a2d6006614fe2b3e81e47377dd2a9
>>>>> c26f8d35f85547c4add392a221af1aab - default default] HTTP exception thrown:
>>>>> Cannot 'evacuate' instance e8485a5e-3623-4184-bcce-cafd56fa60b3 while it is
>>>>> in task_state powering-off
>>>>>
>>>>> So it poweroff all instance on the failed node but does not start them
>>>>> on active nodes
>>>>>
>>>>> What is changed ?
>>>>> Ignazio
>>>>>
>>>>>
>>>>>
>>>
>>> --
>>> ​
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>>>
>>
>
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