Postgres and backup filesystems are over allocated by default

[Tee Ngo]

Brief Description
-----------------
Currently postgres fs allocation is 40G for disk size greater than 240G and 20G for disk size between 240G - 186G inclusive by default. Now that OpenStack services are no longer part of the platform, this filesystem is greatly over-allocated. The default value should be cut in half:
20G for large disk size and 10G for small disk size by default.

The default backup filesystem should therefore be adjusted to 25G and 15G respectively to reflect the reduction of postgres fs allocation.

Severity
--------
Minor

Steps to Reproduce
------------------
N/A

Expected Behavior
------------------
Default filesystems are allocated optimally

Actual Behavior
----------------
Default Postgres and backup filesystems are not allocated optimally

Reproducibility
---------------
100% reproducible

System Configuration
--------------------
Any

Branch/Pull Time/Commit
-----------------------
Master

Last Pass
---------
N/A

Timestamp/Logs
--------------
N/A

Test Activity
-------------
System Test

[Ovidiu Poncea (ovidiuponcea)]

For larger disks the allocation for the backup is ok, 25GB. For smal disks we need to set it to 20GB as the minimum is computed using a formula which is present in multiple parts of the code and I'm reluctant to change it.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/692129

[Ghada Khalil (gkhalil)]

stx.3.0 / low - configuration tuning; no direct system impact

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/692125
Committed: https://git.openstack.org/cgit/starlingx/config/commit/?id=ae9389d658b6233e1923b277d7c8e115cdd49e06
Submitter: Zuul
Branch: master

commit ae9389d658b6233e1923b277d7c8e115cdd49e06
Author: Ovidiu Poncea <email address hidden>
Date: Wed Oct 30 14:39:23 2019 +0200

    Reduce postgres and backup filesystem sizes

    Since openstack is a separate application we reduce the preallocated
    size for the postgresql database and for the backup filesystems.
    Currently postgres fs allocation is 40G for disk size greater than
    240G and 20G for disk size between 240G - 186G inclusive.

    This commit cuts these defaults in half:
     o postgresql will be 20G for large disk size and 10G for small disk
       size by default.
     o backup filesystem will be adjusted to 25G and 20G respectively to
       reflect the reduction of postgres fs allocation.

    Change-Id: I87ce7b90c8d9b28f230ea7a42122215e2dacfc9b
    Partial-Bug: 1850207
    Signed-off-by: Ovidiu Poncea <email address hidden>

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/692129
Committed: https://git.openstack.org/cgit/starlingx/ansible-playbooks/commit/?id=e1fc12b54252588dbf5fffd61a5a1dae2956eee0
Submitter: Zuul
Branch: master

commit e1fc12b54252588dbf5fffd61a5a1dae2956eee0
Author: Ovidiu Poncea <email address hidden>
Date: Wed Oct 30 14:49:30 2019 +0200

    Reduce postgres and backup filesystem sizes

    Since openstack is a separate application we reduce the preallocated
    size for the postgresql database and for the backup filesystems.
    Currently postgres fs allocation is 40G for disk size greater than
    240G and 20G for disk size between 240G - 186G inclusive.

    This commit cuts these defaults in half:
     o postgresql will be 20G for large disk size and 10G for small disk
       size by default.
     o backup filesystem will be adjusted to 25G and 20G respectively to
       reflect the reduction of postgres fs allocation.

    Change-Id: Ic2273f67300d73f26579981cdca2832de1e8ab2f
    Closes-Bug: 1850207
    Depends-On: I87ce7b90c8d9b28f230ea7a42122215e2dacfc9b
    Signed-off-by: Ovidiu Poncea <email address hidden>