Code review comment for lp:~ltrager/maas-images/v3_squashfs_only

Any version of MAAS which can use the V3 stream can deploy SquashFS images. In the current V3 stream if a release has a SquashFS image we only publish the SquashFS image. The only reason Trusty and Precise have yet to goto a SquashFS image is because they aren't available on http://cloud-images.ubuntu.com. If MAAS detects a release in the stream contains both a root-image and a SquashFS image the SquashFS image will be downloaded and the root-image will be ignored[1]. If a SquashFS image is added to an existing release version the root-image will be deleted and the SquashFS image will be downloaded[2]. So once the Trusty SquashFS image is released to the V3 stream no version of MAAS will use the root-image, even if its available.

[1] https://git.launchpad.net/maas/tree/src/maasserver/bootresources.py#n1084
[2] https://git.launchpad.net/maas/tree/src/maasserver/bootresources.py#n652