[Gluster-users] Distributed-replicate across four bricks with two hosts

[Robert Hajime Lanning]

On 06/14/13 13:35, Ziemowit Pierzycki wrote:
> Hi,
>
> I created a distributed-replicated volume across two servers and two
> bricks each.  Here is the configuration:
>
> Volume Name: slice1
> Type: Distributed-Replicate
> Status: Started
> Number of Bricks: 2 x 2 = 4
> Transport-type: tcp
> Bricks:
> Brick1: elkpinfkvm05-bus:/srv/brick1
> Brick2: elkpinfkvm05-bus:/srv/brick2
> Brick3: elkpinfkvm06-bus:/srv/brick1
> Brick4: elkpinfkvm06-bus:/srv/brick2
>
> So naturally the question comes up: how do I know the replication is
> happening across the hosts, not two bricks on the same host?  If one of
> the hosts went down, I want to make sure the storage is still available.

Replica sets are done in order that the bricks are added to the volume.
So, you have the replica set size set to 2, which means every 2 bricks 
are mirrored, down the line.

Brick1 + Brick2 = Replica 1
Brick3 + Brick4 = Replica 2

Then the distribution (DHT) distributes files over Replica 1 and Replica 2.

So, you have an issue here, that both bricks of a replica set are on the 
same host.

-- 
Mr. Flibble
King of the Potato People