[docs] provide details for master node storage planning

[Bogdan Dobrelya]

There are following topics in docs missing the storage planning details for master node:
1)http://docs.mirantis.com/openstack/fuel/fuel-6.0/planning-guide.html#fuel-master-node-hardware-recommendations
2)http://docs.mirantis.com/openstack/fuel/fuel-6.0/planning-guide.html#planning-summary
3)http://docs.mirantis.com/openstack/fuel/fuel-6.0/planning-guide.html#calculating-storage

The documentation should explain:
* how to plan the storage capacities for
   - PostgreSQL DB (shares /var)
   - Remote logs (/var/log partition)
   - Docker images (shares /var)
   - Repository (shares /var)
or at least provide more details about planning /var and /var/log capacities with examples, as currently there is only 50Gb of disk space recommended for the master node, but this would be not enough for large deployments of 100+ nodes.

[Alexander Bozhenko (alexbozhenko)]

After fixing this we can add exact calculations to the docs.
https://bugs.launchpad.net/fuel/+bug/1382515

Related bug, that contain info how we are configuring storage capacities per partition currently:
https://bugs.launchpad.net/fuel/+bug/1415946

[Bogdan Dobrelya (bogdando)]

JFYI, there is also kinda related drafts of planning capacities https://blueprints.launchpad.net/fuel/+spec/manage-logs-with-free-space-consideration, feel free to comment and turn it into the corresponding docs or specs

[Irina Povolotskaya (ipovolotskaya)]

not sure we'll be in time for 6.1. I'm moving the task to 7.0.
It there a great need to update 5.x documentation? I believe, we could focus on 6.x only.

[Michele Fagan (michelefagan)]

Request for new documentation and rewriting of existing doc. Moving to 9.0.

[Alexander Bozhenko (alexbozhenko)]

Our docs still says
https://docs.mirantis.com/openstack/fuel/fuel-8.0/mos-planning-guide.html#sysreq-fuel-mn-hw-reqs
128GB SAS Disk for fuel master
Customers continue to deploy with small disk, and it causing problems for them.

As quick fix, can we just substitute the line:
128GB SAS Disk
with something like this:
Disk size depends on number of nodes that will be deployed using fuel, since all nodes send logs to fuel master node using rsyslog. During installation fuel creates separate partition for /var, where remote logs are stored, and allocates 40% of disk to it. Our recommendation for remote logs partition is 20gb per node. So, if you deploy 10 nodes with fuel you need to have (20*10)*2.5 = 500GB disk for fuel master.

[Bogdan Dobrelya (bogdando)]

That is a high UX issue, raised the prio

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/305037

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/305037
Committed: https://git.openstack.org/cgit/openstack/fuel-docs/commit/?id=35e536286d879d41ebf0976bc283185252e743c0
Submitter: Jenkins
Branch: master

commit 35e536286d879d41ebf0976bc283185252e743c0
Author: Evgeny Konstantinov <email address hidden>
Date: Wed Apr 13 11:21:09 2016 +0300

    Add disk size recommendation

    Change-Id: Ifda01a4f7541d5b3c1e032757c3abd1d0ec8f8c3
    Partial-Bug:#1446668

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

Reviewed: https://review.fuel-infra.org/19554
Submitter: Svetlana Karslioglu <email address hidden>
Branch: master

Commit: 9495fdd5dc6a51e9ec16a78c9a6a16df05633686
Author: Evgeny Konstantinov <email address hidden>
Date: Wed May 4 09:07:36 2016

Add Fuel Master node disk size recommendation
Partial-Bug: #1446668

Change-Id: I4131297b012e6c7aac900ec574b0648dedf7d693

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

Fix proposed to branch: master
Change author: Svetlana Karslioglu <email address hidden>
Review: https://review.fuel-infra.org/20618

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

Reviewed: https://review.fuel-infra.org/20618
Submitter: Michele Fagan <email address hidden>
Branch: master

Commit: 91b4db767a7d6a04f73471e3f627e94c44d3bee7
Author: Svetlana Karslioglu <email address hidden>
Date: Wed May 18 17:52:45 2016

Modified hw reqs for Fuel Master node

Extended the hardware requirements description for the Fuel Master node.

Change-Id: I25b6165e534e39155087184033f4d872185b18bd
Closes-bug: 1446668