On http://download.gluster.org/pub/gluster/glusterfs/3.2/Documentation/AG/html/chap-Administration_Guide-Setting_Volumes.html a warning should be added to prevent customers from expecting replication of changes made directly to bricks.

"""
A volume is a logical collection of bricks where each brick is an export directory on a server in the trusted storage pool. Most of the gluster management operations happen on the volume.

### WARNING GOES HERE ###

You can create new volumes in your storage environment, as needed. When creating a new volume, you must specify the bricks that comprise the volume.
"""