Cinder client incorrectly list the volume size units in GB, the API is actually in GiB

[Kurt Martin]

Both Horizon and the cinder client documents the size paramater in gigabyes(GB) but the API docs(both v1 and v2) list the size units as gibibytes(GiBs). The correct unit should be gibibytes(GiBs)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/240091

[Kurt Martin (kurt-f-martin)]

The LVM driver is in fact creating volumes in gibibytes (GiB), lvdisplay is showing the volume in GiBs... see http://paste.openstack.org/show/477912/ for details. This means that the API is documented correctly. The cinder client (http://paste.openstack.org/show/477913/) and Horizon should actually have the units corrected from GB to GiB. I would like to post patches to both the cinder client and horizon to remove any confusion on the units that Cinder is using.

[Kurt Martin (kurt-f-martin)]

Review for the python-cinderclient: https://review.openstack.org/#/c/241405/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/241405
Committed: https://git.openstack.org/cgit/openstack/python-cinderclient/commit/?id=cb08ce33eb74cb95702081846280a194823d86ae
Submitter: Jenkins
Branch: master

commit cb08ce33eb74cb95702081846280a194823d86ae
Author: Kurt Martin <email address hidden>
Date: Tue Nov 3 15:13:20 2015 -0800

    Fix volume size units to match the API

    Both Horizon and the cinder client documents the size paramater in
    gigabyes(GBs) but the API docs(both v1 and v2) list the size units as
    gibibytes(GiBs). The correct unit should be gibibytes(GiBs). This
    should help in clearing up any confusion on what units are used in
    Cinder.

    Closes-bug: 1511167
    Change-Id: I42e15c18d1f084d435a2be9b343fb2f6c3cf377f

[Doug Fish (drfish)]

Has anyone investigated how nova, glance, ceilometer report data? I'd guess they report data in binary units, which we've labelled as traditional/decimal in Horizon.

I'd think if we do this, we'd need to update all of Horizon, not just the cinder/volume parts.

[Kurt Martin (kurt-f-martin)]

Hi Doug...I've only done the investigation in the cinder client and the cinder create/extend volume API. At least now the cinder client create call matches the cinder API. The majority of storage vendors deal in gibibytes including the LVM reference driver, however, everything else is in gigabytes. If you talk to some people they say GB = GiB, but that is not the case when you get down to the fine details.

[Richard Hagarty (richard-hagarty)]

Storage admins know the difference between GBs and GiBs, and make assumptions based on how the value is tagged/labeled. Since we have real customers who have complained about how we represent size in Horizon, I think we should focus on the cinder pieces first.

I propose that we just modify the labels in the following panels to read "GiB" instead of "GB", and "gibibytes" instead of "gigibytes":

- project -> create volume
- project -> create snapshot
- project -> extend volume
- project -> volume details
- project -> snapshot details
- admin -> volume details
- admin -> snapshot details
- identity:projects -> modify quotas

We know these are "wrong" as the cinder API assumes "GiB".

I realize there are inconsistencies in other services, and even in within Cinder itself (the CLI for quotas uses the term "gigabytes", when it should be "gibibytes"), but the distinction is probably not as important.

We can open additional defects to handle other inconsistencies if they present any "real" confusion to the customer.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/243880

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/243880
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=70ade476b8001ed63cbb371620a035fe1ca7a44a
Submitter: Jenkins
Branch: master

commit 70ade476b8001ed63cbb371620a035fe1ca7a44a
Author: Rich Hagarty <email address hidden>
Date: Tue Nov 10 16:15:53 2015 -0800

    Use "GiB" and "gibibyte" labels in volume panels

    Cinder APIs require size values to be in gibibytes (GiB).
    Horizon panels show these values in gigabytes (GB), which
    confuses storage admins.

    Change-Id: I62ab332d3415f35ead237dd1af5f6a11eb193654
    Partially-Implements: blueprint gb-to-gib-conversion
    Closes-bug: #1511167