[doc] cinder-volume should run as active/standby

[slava valyavskiy]

There are currently concerns over the cinder-volume service ability
to run as a fully active-active service. During the Mitaka timeframe, this is being worked on, see:
   https://blueprints.launchpad.net/cinder/+spec/cinder-volume-active-active-support
   Thus, cinder-volume shall only be running on one of the controller nodes, even if it will be configured on all nodes

This bug has been forked from discussion in https://bugs.launchpad.net/fuel/+bug/1393331/comments/7

[Javier Diaz Jr (javierdiazcharles)]

Customer requested documentation on how to configure this in Mirantis SFDC ticket 12797. Customer is running MOS 6.1. Please advise.

[Fuel Devops McRobotson (fuel-devops-robot)]

Change abandoned by Mariia Zlatkova <email address hidden> on branch: master
Review: https://review.fuel-infra.org/21336
Reason: Abandon

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: stable/8.0
Change author: Mariia Zlatkova <email address hidden>
Review: https://review.fuel-infra.org/21338

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/21338
Submitter: Olga Gusarenko <email address hidden>
Branch: stable/8.0

Commit: 1eff677ea106cf945c1d8be5f967cee181e6f3f9
Author: Mariia Zlatkova <email address hidden>
Date: Fri May 27 14:59:32 2016

[RN MOS8.0] Other known issues

Adds the following known issue to the
MOS8.0 release notes:

- #1528840 cinder-volume should run as active/standby

Change-Id: Iacb191445ed700dac7d1e8330bddad1a66978671
Closes-Bug: #1528840