[ovirt-users] HA without Power Management

Wed Nov 30 13:18:13 UTC 2016

Hi Yaniv,

Yes, the provider gives me access to the power management of the server, by
using the user web portal and their java applet (the provider is OVH, in
case you have worked with their enviroment). Sadly, their IPMI device is
connected to a non accesible network for me, but only accesible by those
"web" means of using their java appleat via the web user portal.

I'm not sure I'm fully understanding your workaround, sorry :/ In any case,
if 4.1 brings the functionality described (hope it does!) it would be more
than enough for my case. Also, I'll try to "play" with the ipmilan to see
if I can get someplace with it. As my main problem is that one of the hosts
is suddenly rebooting with apparently no software reason, what I'll try to
do is to as soon as the host becomes non-responsive, start sending the
"restart" command to it from my hosted-engine (which HA works no matter
power fencing). So, after the unexpected rebooting of the host, a
controlled reboot should take place allowing the VMs to power on in the
other host.

I'll try to make some time next week to give that a try. Hope it works!!!

Thank you guys :)
Seb
PS: Any estimated release date for 4.1? I never found any info in o-virt
project about next releases or "trello" like info to look forward to new
functionalities, etc.

Sebastián Greco
IT Consultant
Cloud Computing - Red Hat - VMware - Zimbra
www.essiprojects.com
*www.essiprojects.co.uk <http://www.essiprojects.co.uk>*

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 UK

On Wed, Nov 30, 2016 at 12:14 PM, Yaniv Kaul <ykaul at redhat.com> wrote:

>
>
> 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
>>>>
>>>> _______________________________________________
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>>>> Users at ovirt.org
>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>
>>>>
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>>
>
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