Unnecessary dependency on qemu-img by powervm driver

[David Peraza]

The nova.virt.powervm.blockdev module makes a call to fetch_to_raw which requires qemu-img on the system running compute node. Since powervm only supports raw files there is no need to make image conversion and therefore depend on qemu-img. Linux on Power RHEL distro does not include quemu-img by default so this could be an issue that could come up on client shops. To avoid this we can just make a call to images.fetch instead of images.fetch_to_raw. I can provide this fix if assigned to me.

[Michael Still (mikal)]

What happens if a user has uploaded an image to glance which isn't in raw format? Surely you have to do conversion then?

[David Peraza (dperaza)]

Michael, in powervm only raw files are supported, I don't even thing you can get a powervm qcow2 or any other format since power uses block-base provisioning are raws will be a direct bit by bit copy of disk devices. Even if we figure out how to get a qcow2 from a power raw, linux on power RHEL for example does not include qemu-img by default so clients and contributors will most likely hit this issue.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/22709

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/22709
Committed: http://github.com/openstack/nova/commit/edf15fdd38c670482848d2407a013a2ec4addd17
Submitter: Jenkins
Branch: master

commit edf15fdd38c670482848d2407a013a2ec4addd17
Author: David Peraza <email address hidden>
Date: Thu Feb 21 23:42:14 2013 +0000

    Removes unnecessary qemu-img dependency on powervm driver

    Fixes bug 1131033

    Power VM driver is using qemu-img through the fetch_to_raw call
    No need to attempt a conversion since power images can only
    be represented with the raw format, removing thus the need for
    any conversions by calling fetch instead of fetch_to_raw.

    Change-Id: I94b46e184cb87924a4754a0a48d9c2013a3eb756