Description of problem:
For applications which needs many individual storage units (formatable), at the same time requiring high performance, gluster need to come up with block storage solution. Because sometime it is hard to maintain too many small volumes. For such use cases which needs independent disk drives it will be effective to support block storage capability.
Databases (Cassandra, Elastic search), VM images, Server boot and etc.
Need to build utilities which help in making it simple and easy to use. Block storage design should qualify for the container use cases(such as Kubernetes) as well.
More discussion at 
Upstream work is almost ready and github link : https://github.com/gluster/gluster-block
The upstream release was done.
One can find the packages at https://download.gluster.org/pub/gluster/gluster-block/
Gluster block storage builds were provided along with tcmu-runner and other dependent packages. testing is been carried out. Issues are getting reported separately. Since the feature is available marking the RFE 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.