1)created tiered volumes with following configurations:

Hot tier            Cold tier
=========          ===========
3way replica       ECvolume(1x[4+2])
3 way replica      2 way replica
2 way replica      3 way replica

All the above scenarios were working and showing up good

[root@rhsqa14-vm4 ~]# gluster v info
 
Volume Name: distrep
Type: Tier
Volume ID: 8f74266f-de75-4cfe-a63d-e2b08a7e3057
Status: Started
Number of Bricks: 10
Transport-type: tcp
Hot Tier :
Hot Tier Type : Distributed-Replicate
Number of Bricks: 2 x 3 = 6
Brick1: 10.70.46.2:/rhs/brick6/distrep
Brick2: 10.70.47.159:/rhs/brick6/distrep
Brick3: 10.70.46.2:/rhs/brick5/distrep
Brick4: 10.70.47.159:/rhs/brick5/distrep
Brick5: 10.70.46.2:/rhs/brick4/distrep
Brick6: 10.70.47.159:/rhs/brick4/distrep
Cold Tier:
Cold Tier Type : Distributed-Replicate
Number of Bricks: 2 x 2 = 4
Brick7: 10.70.47.159:/rhs/brick1/distrep
Brick8: 10.70.46.2:/rhs/brick1/distrep
Brick9: 10.70.47.159:/rhs/brick2/distrep
Brick10: 10.70.46.2:/rhs/brick2/distrep
Options Reconfigured:
performance.readdir-ahead: on
 
Volume Name: ecvol
Type: Tier
Volume ID: f25eecf7-a83e-478c-b73d-1d954d7a78fe
Status: Started
Number of Bricks: 12
Transport-type: tcp
Hot Tier :
Hot Tier Type : Distributed-Replicate
Number of Bricks: 2 x 3 = 6
Brick1: 10.70.46.2:/rhs/brick6/ecvol
Brick2: 10.70.47.159:/rhs/brick6/ecvol
Brick3: 10.70.46.2:/rhs/brick5/ecvol
Brick4: 10.70.47.159:/rhs/brick5/ecvol
Brick5: 10.70.46.2:/rhs/brick4/ecvol
Brick6: 10.70.47.159:/rhs/brick4/ecvol
Cold Tier:
Cold Tier Type : Disperse
Number of Bricks: 1 x (4 + 2) = 6
Brick7: 10.70.47.159:/rhs/brick1/ecvol
Brick8: 10.70.46.2:/rhs/brick1/ecvol
Brick9: 10.70.47.159:/rhs/brick2/ecvol
Brick10: 10.70.46.2:/rhs/brick2/ecvol
Brick11: 10.70.46.2:/rhs/brick3/ecvol
Brick12: 10.70.47.159:/rhs/brick3/ecvol
Options Reconfigured:
cluster.tier-promote-frequency: 6
cluster.tier-demote-frequency: 5
features.record-counters: on
features.ctr-enabled: on
performance.readdir-ahead: on
 
Volume Name: replica3
Type: Tier
Volume ID: 5aa307c6-6a1b-4962-abae-12cf1f502d40
Status: Started
Number of Bricks: 12
Transport-type: tcp
Hot Tier :
Hot Tier Type : Distributed-Replicate
Number of Bricks: 3 x 2 = 6
Brick1: 10.70.46.2:/rhs/brick6/replica3
Brick2: 10.70.47.159:/rhs/brick6/replica3
Brick3: 10.70.46.2:/rhs/brick5/replica3
Brick4: 10.70.47.159:/rhs/brick5/replica3
Brick5: 10.70.46.2:/rhs/brick4/replica3
Brick6: 10.70.47.159:/rhs/brick4/replica3
Cold Tier:
Cold Tier Type : Distributed-Replicate
Number of Bricks: 2 x 3 = 6
Brick7: 10.70.47.159:/rhs/brick1/replica3
Brick8: 10.70.46.2:/rhs/brick1/replica3
Brick9: 10.70.47.159:/rhs/brick2/replica3
Brick10: 10.70.46.2:/rhs/brick2/replica3
Brick11: 10.70.47.159:/rhs/brick3/replica3
Brick12: 10.70.46.2:/rhs/brick3/replica3
Options Reconfigured:
performance.readdir-ahead: on
[root@rhsqa14-vm4 ~]# gluster --version
glusterfs 3.7.1 built on Jun 14 2015 21:55:41
Repository revision: git://git.gluster.com/glusterfs.git
Copyright (c) 2006-2011 Gluster Inc. <http://www.gluster.com>
GlusterFS comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@rhsqa14-vm4 ~]# rpm -qa|grep gluster
glusterfs-libs-3.7.1-3.el6rhs.x86_64
glusterfs-fuse-3.7.1-3.el6rhs.x86_64
glusterfs-3.7.1-3.el6rhs.x86_64
glusterfs-api-3.7.1-3.el6rhs.x86_64
glusterfs-cli-3.7.1-3.el6rhs.x86_64
glusterfs-geo-replication-3.7.1-3.el6rhs.x86_64
glusterfs-debuginfo-3.7.1-3.el6rhs.x86_64
glusterfs-client-xlators-3.7.1-3.el6rhs.x86_64
glusterfs-server-3.7.1-3.el6rhs.x86_64
glusterfs-rdma-3.7.1-3.el6rhs.x86_64
[root@rhsqa14-vm4 ~]# 




hence moving to verified

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-1495.html