Gluster users - Apr 2017 - Quorum replica 2 and arbiter

Hi,

We have a replica 2 volume and we have issue with setting proper quorum.

The volumes used as datastore for vmware/ovirt, the current settings for the
quorum are:



cluster.quorum-type: auto

cluster.server-quorum-type: server

cluster.server-quorum-ratio: 51%



Losing the first node which hosting the first bricks will take the storage
domain in ovirt offline but in the FUSE mount point works fine
"read/write"

Losing the second node or any other node that hosts only the second bricks of
the replication will not affect ovirt storage domain i.e 2nd or 4th ndoes.

As i understand, losing the first brick in replica 2 volumes will render the
volume to read only, but how FUSE mount works in read write ?

Also, can we add an arbiter node to the current replica 2 volume without losing
data ? if yes, does the re-balance bug "Bug 1440635" affect this
process ?

And what happen if we set "cluster.quorum-type: none" and the first
node goes offline ?

Thank you.


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We are evolving a document to answer this question, the wip document is at
https://github.com/karthik-us/glusterdocs/blob/1c97001d482923c2e6a9c566b3faf89d0c32b269/Administrator%20Guide/Split%20brain%20and%20ways%20to%20deal%20with%20it.md

Let us know if you still have doubts after reading this.

On Tue, Apr 18, 2017 at 8:41 AM, Mahdi Adnan <mahdi.adnan at outlook.com>
wrote:
> Hi,
>
> We have a replica 2 volume and we have issue with setting proper quorum.
>
> The volumes used as datastore for vmware/ovirt, the current settings for
> the quorum are:
>
>
>
> cluster.quorum-type: auto
>
> cluster.server-quorum-type: server
>
> cluster.server-quorum-ratio: 51%
>
>
>
> Losing the first node which hosting the first bricks will take the storage
> domain in ovirt offline but in the FUSE mount point works fine
"read/write"
>
> Losing the second node or any other node that hosts only the second bricks
> of the replication will not affect ovirt storage domain i.e 2nd or 4th
> ndoes.
>
> As i understand, losing the first brick in replica 2 volumes will render
> the volume to read only, but how FUSE mount works in read write ?
>
> Also, can we add an arbiter node to the current replica 2 volume without
> losing data ? if yes, does the re-balance bug "Bug 1440635"
affect this
> process ?
>
> And what happen if we set "cluster.quorum-type: none" and the
first node
> goes offline ?
>
> Thank you.
>
> Get Outlook for Android <https://aka.ms/ghei36>
>
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://lists.gluster.org/mailman/listinfo/gluster-users
>


-- 
Pranith
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