[ovirt-users] 4-node oVirt with replica-3 gluster

[Davide Ferrari]

Oh, thanks! Reinstalling all the luster from scratch right now to get it
right. If I run again in the problem I described before I will open another
thread and attach the relevant logs

2016-09-23 16:28 GMT+02:00 Sahina Bose <sabose at redhat.com>:

>
>
> On Fri, Sep 23, 2016 at 7:54 PM, Davide Ferrari <davide at billymob.com>
> wrote:
>
>> Reading the glusterfs docs
>>
>> https://gluster.readthedocs.io/en/latest/Administrator%20Gui
>> de/arbiter-volumes-and-quorum/
>>
>> "In a replica 3 volume, client-quorum is enabled by default and set to
>> 'auto'. This means 2 bricks need to be up for the writes to succeed. Here
>> is how this configuration prevents files from ending up in split-brain:"
>>
>> So this means that if one of the machines with the 2 bricks (arbiter &
>> normal) fails, the otherbrick will be set RO, or am I missing something?
>> I mean, this config will be better in case of a network loss, and thus a
>> split brain, but it's far worse in case of a machine failing or being
>> rebooted for maintenance.
>>
>
> See the updated vol create command - you should set it up such that 2
> bricks in a sub-volume are not from the same host, thus you avoid the
> problem you describe above
>
>
>>
>>
>> 2016-09-23 16:11 GMT+02:00 Davide Ferrari <davide at billymob.com>:
>>
>>>
>>>
>>> 2016-09-23 15:57 GMT+02:00 Sahina Bose <sabose at redhat.com>:
>>>
>>>>
>>>> You could do this - where Node3 & Node 2 also has arbiter bricks.
>>>> Arbiter bricks only store metadata and requires very low storage capacity
>>>> compared to the data bricks.
>>>>
>>>> Node1  Node2     Node3        Node4
>>>> brick1   brick1      arb-brick
>>>>             arb-brick  brick1        brick1
>>>>
>>>
>>> Ok, cool! And this won't pose any problem if Node2 or Node4 fail?
>>>
>>> The syntax shuld be this:
>>>
>>> gluster volume create data replica 3 arbiter 1 node1:/brick node2:/brick
>>> node2:/arb_brick node3:/brick node4:/brick node4:/arb_brick
>>>
>>> is not a problem having more than a brick on the same host for the
>>> volume create syntax?
>>>
>>> Thanks again
>>>
>>> --
>>> Davide Ferrari
>>> Senior Systems Engineer
>>>
>>
>>
>>
>> --
>> Davide Ferrari
>> Senior Systems Engineer
>>
>
>


-- 
Davide Ferrari
Senior Systems Engineer
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