[Gluster-users] Convert replica 2 to replica 3 arbiter 1

[Russell Purinton]

Is using arbiter unnecessary for me since I have more than 2 servers in the pool anyway?


> On Mar 29, 2016, at 1:36 PM, Atin Mukherjee <atin.mukherjee83 at gmail.com> wrote:
> 
> 
> -Atin
> Sent from one plus one
> On 29-Mar-2016 10:43 pm, "Russell Purinton" <russell.purinton at gmail.com <mailto:russell.purinton at gmail.com>> wrote:
> >
> > I have used the add-brick command in the past but I’m not sure how to go about using it to do this…
> >
> > Could anyone provide an example?
> >
> > As shown below, the current setup, xs141 is replica with xs138.  xs139 is replica with xs140.  I would like to have 139 serve as arbiter for 141 and 138.   And I’d like 141 to serve as arbiter for 139 and 140.
> 
> I don't think that's possible. IIRC, the last brick in the replica pair is considered to be an arbiter brick and I am not aware of any changes in the  behaviour post that. So in short, if you execute add-brick then all the new bricks will be considered as arbiter IMO.
> 
> Ravi can correct me otherwise.
> >
> >> On Mar 29, 2016, at 1:07 PM, Atin Mukherjee <atin.mukherjee83 at gmail.com <mailto:atin.mukherjee83 at gmail.com>> wrote:
> >>
> >> -Atin
> >> Sent from one plus one
> >> On 29-Mar-2016 10:21 pm, "Russell Purinton" <russell.purinton at gmail.com <mailto:russell.purinton at gmail.com>> wrote:
> >> >
> >> > I have several existing volumes configured in the following way:
> >> >
> >> > Volume Name: sonic001
> >> > Type: Distributed-Replicate
> >> > Volume ID: 362eb3a8-c211-4f35-bcd3-87785c51f15c
> >> > Status: Started
> >> > Number of Bricks: 4 x 2 = 8
> >> > Transport-type: tcp
> >> > Bricks:
> >> > Brick1: xs141:/brick1/sonic001p0r0
> >> > Brick2: xs138:/brick1/sonic001p0r1
> >> > Brick3: xs139:/brick1/sonic001p1r0
> >> > Brick4: xs140:/brick1/sonic001p1r1
> >> > Brick5: xs141:/brick0/sonic001p2r0
> >> > Brick6: xs138:/brick0/sonic001p2r1
> >> > Brick7: xs139:/brick0/sonic001p4r0
> >> > Brick8: xs140:/brick0/sonic001p3r1
> >> >
> >> > I recently learned that replica 2 can’t be considered HA because of the split brain scenario that would occur if a network partition occurred.   I also recently learned that using replica 3 arbiter 1 was a way to solve this problem without consuming additional space.
> >> >
> >> > Is there a way I can change this existing volume to be replica 3 arbiter 1, or do I need to create new volumes and rsync the data?
> >>
> >> I think you should be able to convert the volume topology using add-brick command.
> >>
> >> >
> >> > Thanks,
> >> >
> >> > Russ
> >> >
> >> > _______________________________________________
> >> > Gluster-users mailing list
> >> > Gluster-users at gluster.org <mailto:Gluster-users at gluster.org>
> >> > http://www.gluster.org/mailman/listinfo/gluster-users <http://www.gluster.org/mailman/listinfo/gluster-users>
> >>
> >> -Atin
> >> Sent from one plus one
> >
> >

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