[ovirt-users] hyperconverged question

Fri Sep 1 05:33:41 UTC 2017

Hi all:

Sorry to hijack the thread, but I was about to start essentially the same
thread.

I have a 3 node cluster, all three are hosts and gluster nodes (replica 2 +
arbitrar).  I DO have the mnt_options=backup-volfile-servers= set:

storage=192.168.8.11:/engine
mnt_options=backup-volfile-servers=192.168.8.12:192.168.8.13

I had an issue today where 192.168.8.11 went down.  ALL VMs immediately
paused, including the engine (all VMs were running on host2:192.168.8.12).
I couldn't get any gluster stuff working until host1 (192.168.8.11) was
restored.

What's wrong / what did I miss?

(this was set up "manually" through the article on setting up self-hosted
gluster cluster back when 4.0 was new..I've upgraded it to 4.1 since).

Thanks!
--Jim

On Thu, Aug 31, 2017 at 12:31 PM, Charles Kozler <ckozleriii at gmail.com>
wrote:

> Typo..."Set it up and then failed that **HOST**"
>
> And upon that host going down, the storage domain went down. I only have
> hosted storage domain and this new one - is this why the DC went down and
> no SPM could be elected?
>
> I dont recall this working this way in early 4.0 or 3.6
>
> On Thu, Aug 31, 2017 at 3:30 PM, Charles Kozler <ckozleriii at gmail.com>
> wrote:
>
>> So I've tested this today and I failed a node. Specifically, I setup a
>> glusterfs domain and selected "host to use: node1". Set it up and then
>> failed that VM
>>
>> However, this did not work and the datacenter went down. My engine stayed
>> up, however, it seems configuring a domain to pin to a host to use will
>> obviously cause it to fail
>>
>> This seems counter-intuitive to the point of glusterfs or any redundant
>> storage. If a single host has to be tied to its function, this introduces a
>> single point of failure
>>
>> Am I missing something obvious?
>>
>> On Thu, Aug 31, 2017 at 9:43 AM, Kasturi Narra <knarra at redhat.com> wrote:
>>
>>> yes, right.  What you can do is edit the hosted-engine.conf file and
>>> there is a parameter as shown below [1] and replace h2 and h3 with your
>>> second and third storage servers. Then you will need to restart
>>> ovirt-ha-agent and ovirt-ha-broker services in all the nodes .
>>>
>>> [1] 'mnt_options=backup-volfile-servers=<h2>:<h3>'
>>>
>>> On Thu, Aug 31, 2017 at 5:54 PM, Charles Kozler <ckozleriii at gmail.com>
>>> wrote:
>>>
>>>> Hi Kasturi -
>>>>
>>>> Thanks for feedback
>>>>
>>>> > If cockpit+gdeploy plugin would be have been used then that would
>>>> have automatically detected glusterfs replica 3 volume created during
>>>> Hosted Engine deployment and this question would not have been asked
>>>>
>>>> Actually, doing hosted-engine --deploy it too also auto detects
>>>> glusterfs.  I know glusterfs fuse client has the ability to failover
>>>> between all nodes in cluster, but I am still curious given the fact that I
>>>> see in ovirt config node1:/engine (being node1 I set it to in hosted-engine
>>>> --deploy). So my concern was to ensure and find out exactly how engine
>>>> works when one node goes away and the fuse client moves over to the other
>>>> node in the gluster cluster
>>>>
>>>> But you did somewhat answer my question, the answer seems to be no (as
>>>> default) and I will have to use hosted-engine.conf and change the parameter
>>>> as you list
>>>>
>>>> So I need to do something manual to create HA for engine on gluster?
>>>> Yes?
>>>>
>>>> Thanks so much!
>>>>
>>>> On Thu, Aug 31, 2017 at 3:03 AM, Kasturi Narra <knarra at redhat.com>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>>    During Hosted Engine setup question about glusterfs volume is being
>>>>> asked because you have setup the volumes yourself. If cockpit+gdeploy
>>>>> plugin would be have been used then that would have automatically detected
>>>>> glusterfs replica 3 volume created during Hosted Engine deployment and this
>>>>> question would not have been asked.
>>>>>
>>>>>    During new storage domain creation when glusterfs is selected there
>>>>> is a feature called 'use managed gluster volumes' and upon checking this
>>>>> all glusterfs volumes managed will be listed and you could choose the
>>>>> volume of your choice from the dropdown list.
>>>>>
>>>>>     There is a conf file called /etc/hosted-engine/hosted-engine.conf
>>>>> where there is a parameter called backup-volfile-servers="h1:h2" and if one
>>>>> of the gluster node goes down engine uses this parameter to provide ha /
>>>>> failover.
>>>>>
>>>>>  Hope this helps !!
>>>>>
>>>>> Thanks
>>>>> kasturi
>>>>>
>>>>>
>>>>>
>>>>> On Wed, Aug 30, 2017 at 8:09 PM, Charles Kozler <ckozleriii at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hello -
>>>>>>
>>>>>> I have successfully created a hyperconverged hosted engine setup
>>>>>> consisting of 3 nodes - 2 for VM's and the third purely for storage. I
>>>>>> manually configured it all, did not use ovirt node or anything. Built the
>>>>>> gluster volumes myself
>>>>>>
>>>>>> However, I noticed that when setting up the hosted engine and even
>>>>>> when adding a new storage domain with glusterfs type, it still asks for
>>>>>> hostname:/volumename
>>>>>>
>>>>>> This leads me to believe that if that one node goes down (ex:
>>>>>> node1:/data), then ovirt engine wont be able to communicate with that
>>>>>> volume because its trying to reach it on node 1 and thus, go down
>>>>>>
>>>>>> I know glusterfs fuse client can connect to all nodes to provide
>>>>>> failover/ha but how does the engine handle this?
>>>>>>
>>>>>> _______________________________________________
>>>>>> Users mailing list
>>>>>> Users at ovirt.org
>>>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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