Comment 4 for bug 1545018

Reviewed: https://review.openstack.org/287912
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-os_swift/commit/?id=81aecda55fd612ff095f1546521b48dd0216ffbd
Submitter: Jenkins
Branch: master

commit 81aecda55fd612ff095f1546521b48dd0216ffbd
Author: Andy McCrae <email address hidden>
Date: Fri Feb 12 15:04:49 2016 +0000

    Expose and set a default fallocate_reserve value

    When swift disks fill up completely it becomes difficult to perform
    operations since delete operations require a write.

    By setting this value we can ensure that PUT requests won't happen when
    the disk space is below the threshold set (in bytes). This will not
    govern rsyncs, which can still happen to fill up the disks, but assuming
    a reasonably uniform distribution of data this should help prevent disks
    from filling up.

    Change-Id: I753de5e5ed09a21571575ef51c38752edc0730cb
    Closes-Bug: #1545018