Comment 3 for bug 1881727

Reviewed: https://review.opendev.org/734421
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d2af7ca7a5c862f53f18c00ac76fc85336fa79e6
Submitter: Zuul
Branch: master

commit d2af7ca7a5c862f53f18c00ac76fc85336fa79e6
Author: esubramanian <email address hidden>
Date: Mon Jun 8 23:08:30 2020 -0700

    Removes the delta file once image is extracted

    When creating a live snapshot of an instance, nova creates a
    copy of the instance disk using a QEMU shallow rebase. This
    copy - the delta file - is then extracted and uploaded. The
    delta file will eventually be deleted, when the temporary
    working directory nova is using for the live snapshot is
    discarded, however, until this happens, we will use 3x the
    size of the image of host disk space: the original disk,
    the delta file, and the extracted file. This can be problematic
    when concurrent snapshots of multiple instances are requested
    at once.

    The solution is simple: delete the delta file after it has
    been extracted and is no longer necessary.

    Change-Id: I15e9975fa516d81e7d34206e5a4069db5431caa9
    Closes-Bug: #1881727