Description of problem:
++++++++++++++++++

The OCS 3.11 Deployment guide includes checking the glusterfs-client packages are installed or not in all the OCP nodes : section- 3.1.3 and 3.2.3. 

But it doesn't explicitly mention that the client package should either be the same OR only one version lower than the gluster-rhgs version(which differs based on the selected OCS version). Only checking the gluster-client is installed or not is not sufficient, we need to have the correct version installed.

Reason for ask:
===============
During ansible OCP install(deploy_cluster), a task is executed to install glusterfs-client packages on all OCP nodes. Depending on the repo enabled, we may end up in situations where the client version installed is either lower or higher than the gluster rhgs version in OCS gluster pods. 

Hence, it would be advisable to add a note to make sure the glusterfs-client version is appropriate, based on the selected OCS version(aka gluster server version in OCS pods)


Document link
=====================

Chapter 3. Verify Prerequisites

Section - https://access.redhat.com/documentation/en-us/red_hat_openshift_container_storage/3.11/html-single/deployment_guide/#OCP_Req_for_CNS

Section - https://access.redhat.com/documentation/en-us/red_hat_openshift_container_storage/3.11/html-single/deployment_guide/#OCP_Req_for_CRS



One example
==============

Currently, in RHEL 7.6 ,
if repo rh-gluster-3-client-for-rhel-7-server-rpms is enabled  
-------------------------------------------------------------

gluster-client package =3.12.2-25

if only repo: rhel-7-server-rpms is enabled
------------------------------------------
gluster-client version = 3.12.2-18.el7.x86_64


But if we install OCS 3.11, the gluster-server rpm in pods= 3.12.2-18.2

Hence, we may end up in a situation where the client and server packages are not of the recommended version of compatibility.

# yum provides glusterfs-client|grep -B3  3.12.2

glusterfs-fuse-3.12.2-25.el7.x86_64 : Fuse client
Repo        : rh-gluster-3-client-for-rhel-7-server-rpms
Matched from:
Provides    : glusterfs-client = 3.12.2-25.el7


glusterfs-fuse-3.12.2-18.el7.x86_64 : Fuse client
Repo        : rhel-7-server-rpms
Matched from:
Provides    : glusterfs-client = 3.12.2-18.el7