[Gluster-users] Gluster-users Digest, Vol 95, Issue 32

[paf1 at email.cz]

Hello Andreas,
we are testing stripe 2 replica 3 arbiter 1 gluster volume, it's running, but not supported by Ovirt 3.5.6.2 ( can't create 'storage" , with "unsupported" message )
This is running in 5 node gluster. Node 5 dedicated only for arbiter bricks and has no "big disks".

exam:
gluster volume create AAAA stripe 2 replica 3 arbiter 1  \
brick1_data:/replica1/GFS  brick2_data:/replica1/GFS brick5_arbiter:/replica1/GFS   \
brick3_data:/replica2/GFS  brick5_data:/replica2/GFS brick5_arbiter:/replica2/GFS

Arbiter node hold only metadata and is common for all volumes. Can run VMs ( data over interconnect )


pbauer
  

Message: 1
Date: Thu, 24 Mar 2016 18:26:53 +0530
From: Ravishankar N<ravishankar at redhat.com>
To:abauer at magix.net, gluster-users<gluster-users at gluster.org>
Subject: Re: [Gluster-users] Automatic arbiter volumes on
	distributed/replicated volumes with replica 2?
Message-ID:<56F3E415.9040103 at redhat.com>
Content-Type: text/plain; charset=utf-8; format=flowed

On 03/24/2016 04:30 PM, Andr? Bauer wrote:

> So if you have a 4 node cluster is it realy needed to have a third
> replica? Imho the 2 of the nodes could also be used as arbiters?

I'm not sure I understand. The 'arbiter' volume is a special type of
replica volume where the 3rd brick of that replica (for every replica)
only holds metadata. So if you're asking if this brick itself can be
co-located on a node which holds the other 'data' bricks of the volume,
then yes that is possible.
-Ravi

> Does it make sense to open a feature request in the bugtracker?
>
> Regards
> Andr?
>
> Am 24.03.2016 um 11:02 schrieb Ravishankar N:
>> On 03/24/2016 02:39 PM, Andr? Bauer wrote:
>>> Hi List,
>>>
>>> we just upgraded out 4 node cluster from 3.5.8 to 3.7.8.
>>>
>>> Because of replica 2 on all volumes i run into problems with read only
>>> file systems of vm images when running on 3.5.x. As i know now the
>>> solution would be to have replica 3 or at least use arbiter volumes.
>>>
>>> Yesterday i stumbled over this post in the list which i missed before
>>> (damn spam filter):
>>>
>>> https://www.gluster.org/pipermail/gluster-users/2015-November/024191.html
>>>
>>> Steve Dainard is pointing out that 3.7.x uses an automatic arbiter, when
>>> you have 4 nodes configured as distributed/replicated.
>>>
>>> Is this true? Could not find something about it in the documentation :-/
>> There is no 'automatic' arbiter for replica 2. I think he was referring
>> to the dummy node peer probed for maintaining server quorum.
>> -Ravi
>>> Would be nice i could save on having 2 more nodes this way.
>>>
>>> If not, is there a chance to see such feature in the future?
>>>
>>>
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