Comment 2 for bug 1030010

Reviewed: https://review.openstack.org/11020
Committed: http://github.com/openstack/nova/commit/f94ae65640d16124f9d7fad8c726b185f0398452
Submitter: Jenkins
Branch: master

commit f94ae65640d16124f9d7fad8c726b185f0398452
Author: Eoghan Glynn <email address hidden>
Date: Wed Aug 1 16:28:04 2012 +0000

    Enforce quota limitations for instance resize.

    Fixes LP 1030010.

    Close off a back-door allowing users to go over-quota on ram
    and/or cores by creating a tiny instance and then resizing
    to any size regardless of the remaining usage headroom.

    The quota management logic is distributed in the sense that
    the reservations are passed with the RPC casts that may fail
    silently, so that the rollback or commit is handled by the
    actor finalizing the resize/confirmation/reversion.

    Up-sizing requires there is sufficient quota headroom upfront
    to accommodate the larger size, whereas conversely down-sizing
    only results in a usage reduction when the resize is confirmed.

    Change-Id: I2b1cbb098c79e37d7ad19221fe23657eb018eae6