create_nested_snapshots_and_attach_volume failed due incorrect vol size

[Anton Arefiev]

Scenario create_nested_snapshots_and_attach_volume failed with error:

BadRequest: Invalid input received: Volume size 4GB cannot be smaller than the snapshot size 5GB. They must be >= original snapshot size. (HTTP 400)

The problem is mismatching size for volume and snapshot resources

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/185336

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/185336
Committed: https://git.openstack.org/cgit/openstack/rally/commit/?id=4e8078bf9ce8ac1c350f7c6a7a09db910991a6e2
Submitter: Jenkins
Branch: master

commit 4e8078bf9ce8ac1c350f7c6a7a09db910991a6e2
Author: Anton Arefiev <email address hidden>
Date: Mon May 25 12:19:05 2015 +0300

    Fix cinder scenario: create nested snapshots

    Volume size cannot be smaller than the snapshot size. They
    must be >= original snapshot size. This change fix this
    possible size mismatching, occurs due creating resouces with
    random size.

    Change-Id: Ib95ff354a2d2f0b59ff982365729d306618294c9
    Closes-Bug: #1457866