[ovirt-users] hyperconverged question

[Charles Kozler]

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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