Enable disk usage report for ephemeral (instance detail list )

[Anna Shen]

Currently, only when volume is enabled, end user will see disk usage report (total size and used) while get instance by instance_id.
when volume is off, customers might also need to know the disk usage report for ephemeral, although the device type is not exposed to them.

[Anna Shen (ruiyuan-shen)]

/trove/etc/trove/trove.conf.sample

volume support:
trove_volume_support = True
device_path = /dev/vdb

ephemeral:
trove_volume_support = False
device_path = /dev/vdb

root partition:
trove_volume_support = False
device_path = None

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/33907
Committed: http://github.com/openstack/trove/commit/07d9bafd129374677f92c181b76d83857cce2547
Submitter: Jenkins
Branch: master

commit 07d9bafd129374677f92c181b76d83857cce2547
Author: Anna Shen <email address hidden>
Date: Thu Jun 20 17:39:58 2013 -0700

    Enable disk usage view in instance detail view

    - support both volume and ephemeral modes

    Bug #1194597

    Change-Id: I407268a74d979f95969e29cf54191f92afe0c3e9