upstream patch : https://review.gluster.org/#/c/18016

Build: 3.12.2-5

Set the max port number as 49200 in the /etc/glusterfs/glusterd.vol, restarted glusterd to get the changes reflected from the glusterd.vol file.

glusterd should not be able to allocate the port beyond the max port range

when the port number exceeds the limit set in the vol file, the volume start will fail as below

[root@dhcp37-54 ~]# gluster vol start testvol_z
volume start: testvol_z: failed: Commit failed on localhost. Please check log file for details 

Glusterd log saying all the ports are exhausted
[2018-03-13 09:07:42.855879] E [MSGID: 106612] [glusterd-utils.c:2016:glusterd_volume_start_glusterfs] 0-management: All the ports in the range are exhausted, can't start brick /bricks/brick0/testvol_100z for volume testvol_z

comment out the max-port in glusterd.vol file and restart glusterd. Now the default max port is set to 65535. Now volume start succeeds

[root@dhcp37-54 ~]# gluster vol start testvol_z
volume start: testvol_z: success

Hence marking it as verified

Updated the doc text. Kindly review and confirm

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://access.redhat.com/errata/RHSA-2018:2607