Gluster users - Apr 2015 - Problem adding brick to an existing volume

Hi Gluster Users,

I am hoping that someone can help me put me on the right track maybe ..

Objective is to have a high available, extensible storage cluster with a 
fair rate of redundancy.

I was thinking of a cluster of multiple machines, starting with 2 
servers, 2 disks each and a config of

Volume Name: originals
Type: Distributed-Replicate
Volume ID: xx
Status: Started
Number of Bricks: 2 x 2 = 4
Transport-type: tcp

Volume: originals
Brick srv1:/srv/vol1 (/dev/sdb1 500GB)
Brick srv1:/srv/vol2 (/dev/sdc1 500GB)
Brick srv2:/srv/vol1 (/dev/sdb1 500GB)
Brick srv2:/srv/vol2 (/dev/sdb1 500GB)

Now I would like to add another server with JUST 1 500GB disk, peer 
probe and everything is fine so far, but when it comes to adding the brick:

root at srvdst01:~# gluster volume add-brick videos srv3:/srv/vol1
volume add-brick: failed: Incorrect number of bricks supplied 1 with count 2

Ok, trying to change the num of replica's or whatever just results in

root at srvdst01:~# gluster volume add-brick videos replica 3 
srv3:/srv/vol1 (or vol3 or vol4, this doesnt matter)
volume add-brick: failed: Operation failed

No way to get around this .. What do I have to do ? Add two bricks in 1 
command ? How would it work in the future when I gets to production 
machines with each 2 or even more disks ?

Were great someone could gimme a hint.

Its gluster 3.4.2-1ubuntu1 amd64 on ubuntu 14.04 LTS.

regards, Oliver

On 04/28/2015 04:41 PM, Oliver wrote:
> Hi Gluster Users,
> 
> I am hoping that someone can help me put me on the right track maybe ..
> 
> Objective is to have a high available, extensible storage cluster with a
> fair rate of redundancy.
> 
> I was thinking of a cluster of multiple machines, starting with 2
> servers, 2 disks each and a config of
> 
> Volume Name: originals
> Type: Distributed-Replicate
> Volume ID: xx
> Status: Started
> Number of Bricks: 2 x 2 = 4
> Transport-type: tcp
> 
> Volume: originals
> Brick srv1:/srv/vol1 (/dev/sdb1 500GB)
> Brick srv1:/srv/vol2 (/dev/sdc1 500GB)
> Brick srv2:/srv/vol1 (/dev/sdb1 500GB)
> Brick srv2:/srv/vol2 (/dev/sdb1 500GB)
> 
> Now I would like to add another server with JUST 1 500GB disk, peer
> probe and everything is fine so far, but when it comes to adding the brick:
> 
> root at srvdst01:~# gluster volume add-brick videos srv3:/srv/vol1
> volume add-brick: failed: Incorrect number of bricks supplied 1 with
> count 2
> 
> Ok, trying to change the num of replica's or whatever just results in
> 
> root at srvdst01:~# gluster volume add-brick videos replica 3
> srv3:/srv/vol1 (or vol3 or vol4, this doesnt matter)
> volume add-brick: failed: Operation failed
> 
> No way to get around this .. What do I have to do ? Add two bricks in 1
> command ? How would it work in the future when I gets to production
> machines with each 2 or even more disks ?
Since the existing configuration is 2 X 2 and if you are willing to
continue to make this volume a distribute-replicate one, you should add
two bricks saying gluster v add-brick videos replica 2 <brick1>
<brick2>

However, I think you could still convert it from replica 2 to replica 3
with the command what you attempted. Can you share the glusterd log file
of all the nodes to debug it further.

Adding Ravi in cc.

~Atin
> 
> Were great someone could gimme a hint.
> 
> Its gluster 3.4.2-1ubuntu1 amd64 on ubuntu 14.04 LTS.
> 
> regards, Oliver
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://www.gluster.org/mailman/listinfo/gluster-users
> 
-- 
~Atin

Hi,
> root at srvdst01:~# gluster volume add-brick videos srv3:/srv/vol1
> volume add-brick: failed: Incorrect number of bricks supplied 1 with count
2
It is a distribute-replica type of volume with replica count 2. Hence 
whenever you add bricks you have to add bricks in multiple of 2. 
Hence the error - Incorrect number of bricks supplied 1 with count 2.
> Ok, trying to change the num of replica's or whatever just results in
> root at srvdst01:~# gluster volume add-brick videos replica 3 
> srv3:/srv/vol1 (or vol3 or vol4, this doesnt matter)
> volume add-brick: failed: Operation failed
You can just add bricks in multiple of 2 instead of changing the replica count.
Also in the above
command you have given the replica count as 3 yet supplied just one brick, hence
the command fails.



Thanks,
Sakshi Bansal