Comment 17 for bug 1804125

Reviewed: https://review.openstack.org/623547
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=5c7638bab40bd6cfdbc199527d3a8c86bde40897
Submitter: Zuul
Branch: stable/queens

commit 5c7638bab40bd6cfdbc199527d3a8c86bde40897
Author: Matt Riedemann <email address hidden>
Date: Wed Nov 28 17:07:11 2018 -0500

    Note the aggregate allocation ratio restriction in scheduler docs

    This borrows from the release note in change
    I01f20f275bbd5451ace5c1e6f41ab38d488dae4e to document the
    regression, introduced in Ocata, where allocation ratio settings
    in the aggregate core/ram/disk filters are not honored because
    of placement being used by the FilterScheduler.

    While there is related work going on around this in
    blueprint initial-allocation-ratios and
    blueprint placement-aggregate-allocation-ratios, it is still
    a limitation in the current code base and needs to be called
    out in the docs.

    Change-Id: Ifaf596a8572637f843f47daf5adce394b0365676
    Related-Bug: #1804125
    (cherry picked from commit d65c18a0a9f02e6d37f2b87ff61f1740c8bfc867)
    (cherry picked from commit 899b4ca5a248eba252d3c89e373f8a787d68749c)