Gluster users - Apr 2017 - Multiple bricks on same node

I apologize if this has been answered before, I haven't found a
satisfying explanation.

I've just set up a new gluster. We have 4 servers and each has 3 RAIDS
with separate raid controller. I wanted to create one giant data space
and tried:

    $ gluster volume create Data replica 2 transport tcp
    host1:/brick1/data host1:/brick2/data host1:/brick3/data [...]
    host4:/brick3/data

This gave me the error message:

    volume create: MRIData: failed: Multiple bricks of a replicate
    volume are present on the same server. This setup is not optimal.
    Use 'force' at the end of the command if you want to override this
    behavior.

The 'force' option allowed me to create a volume and everything seems to
work. The question is, whys is this not optimal ? What are the potential
pitfalls ? I don't want to find myself with an unusable data space.
Also, does it make a difference the order in which I specify the bricks ?

Thanks,

-- 
Valerio Luccio             (212) 998-8736
Center for Brain Imaging   4 Washington Place, Room 158
New York University        New York, NY 10003

    "In an open world, who needs windows or gates ?"

-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.gluster.org/pipermail/gluster-users/attachments/20170404/8ddc9891/attachment.html>

You have to specify the correct order of brick forming the same replica set

In example:

host1:brick1 host2:brick2 host3:brick3 host1:brick4 host2:brick5
host3:brick6

What you did is forming a replica set with all bricks on the same host,
thus an host failure will bring your cluster down

Il 4 apr 2017 8:27 PM, "Valerio Luccio" <valerio.luccio at
nyu.edu> ha scritto:
> I apologize if this has been answered before, I haven't found a
satisfying
> explanation.
> I've just set up a new gluster. We have 4 servers and each has 3 RAIDS
> with separate raid controller. I wanted to create one giant data space and
> tried:
>
> $ gluster volume create Data replica 2 transport tcp host1:/brick1/data
> host1:/brick2/data host1:/brick3/data [...] host4:/brick3/data
>
> This gave me the error message:
>
> volume create: MRIData: failed: Multiple bricks of a replicate volume are
> present on the same server. This setup is not optimal. Use 'force'
at the
> end of the command if you want to override this behavior.
>
> The 'force' option allowed me to create a volume and everything
seems to
> work. The question is, whys is this not optimal ? What are the potential
> pitfalls ? I don't want to find myself with an unusable data space.
> Also, does it make a difference the order in which I specify the bricks ?
>
> Thanks,
>
> --
> Valerio Luccio             (212) 998-8736
> Center for Brain Imaging   4 Washington Place, Room 158
> New York University        New York, NY 10003
>
>     "In an open world, who needs windows or gates ?"
>
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://lists.gluster.org/mailman/listinfo/gluster-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.gluster.org/pipermail/gluster-users/attachments/20170404/54d92655/attachment.html>