Document URL: 
  https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.2/html/administration_guide/sect-Recommended-Configuration_Dispersed

Section Number and Name: 
  11.12. Recommended Configurations - Dispersed Volume
  Example 1

Describe the issue: 
  When creating a 4+2 dispersed volume per these instructions, the create command returns an error.  This has been replicated in my local test environment.

gluster volume create testvol disperse-data 4 redundancy 2 transport tcp \
rhgs3-1:/mnt/bricks/brick1/data \
rhgs3-1:/mnt/bricks/brick2/data \
rhgs3-2:/mnt/bricks/brick1/data \
rhgs3-2:/mnt/bricks/brick2/data \
rhgs3-3:/mnt/bricks/brick1/data \
rhgs3-3:/mnt/bricks/brick2/data

volume create: testvol: failed: Multiple bricks of a disperse 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.

Suggestions for improvement: 
  The docs should be changed to reflect the need for the 'force' option if this is indeed a supported configuration.
 
Additional information: 
  Ultimately the customer wants to create a 2x(4+2) Distributed-Dispersed volume utilizing 12 bricks on 3 nodes.  The error when trying to create even a simple dispersed volume leads them to believe it may not be a supported configuration.

Please let me know if you need any additional information.