[ovirt-users] HA without Power Management

[Yaniv Kaul]

On Tue, Nov 29, 2016 at 7:00 AM, Sebastian Greco <sgreco at essiprojects.com>
wrote:

> Hi Oved!
>
> That's a perfect explanation. Do we have a release date for 4.1? I'm
> currently working with RHV in my production enviroment.
>
> I may don't have the opportunity to wait for 4.1 to see the light as all
> my customers VMs (im a web hoster) run on a non HA cluster as my provider
> does not give me access to the IPMI. If anyone knows anyway to workaround
> this limitation please do let me know.
>
Does he give you access to a smart power grid? If so, you can probably use
that as a fencing mechanism. If there is no access via IPMI nor power, how
can you cycle a stuck host?

A not very good workaround is to run the VMs themselves pinned to different
hosts with a clustering between them. I think it's a bad idea (wasteful),
but it is HA. And in some applications it can be active-active.
You can use virtio-SCSI with passthrough to do SCSI based fencing on a
shared disk (quorum disk), for example.

Y.


> Thanks a lot!
>
> El 28 nov. 2016 9:12 p. m., "Oved Ourfali" <oourfali at redhat.com> escribió:
>
>> Hi Sebastian
>>
>> Currently in case a host is not responding, the only way to make sure no
>> vms are running on it is to fence it, and we only support fencing through
>> power management.
>>
>> In 4.1 we plan to have limited options for storage fencing. This will
>> mean that if a host is not responding then we try to run HA VMs on another
>> host. If the host is still up then it will fail, as the non responsive host
>> is the one holding the lock. If, however, the host is really dead, then the
>> run VM should succeed.
>>
>> So, a VM should be up and running, but it might run on a host that has
>> connectivity issues.
>>
>> Better than what you have now, but still partial. I guess this might get
>> improved during 4.2.
>>
>> Regards,
>> Oved
>>
>> On Nov 28, 2016 18:29, "Sebastian Greco" <sgreco at essiprojects.com> wrote:
>>
>>> Hi,
>>>
>>> Is there any way to have HA in a cluster which hosts have not got
>>> configured the "Power Management"?
>>>
>>> In my scenario I have 2 hosts (v4) on OVH  and a hosted-engine to manage
>>> them. Thing is that OVH does not allow direct communication with the hosts
>>> IPMI interface. IPMI is only available in the "customer area" under a java
>>> applet as that interface is connected to a non accesible network. So,
>>> having no access to this interface I find myself in a situation in which I
>>> lost all my HA functionality :(
>>>
>>> Any help would be more than welcome.
>>>
>>> Sebas
>>>
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20161130/57c613d5/attachment-0001.html>