Windows image page should mention using qcow2 in ceph back envs is a bad idea

We mostly use ceph backed image and volume services in our customer envs, and using qcow2 images is expensive as the image has to be converted to raw to be uploaded.

This causes timeouts in horizon when creating instances from qcow2 windows images, due to the time it takes to convert the often large files involved.

If it would be possible just to make a note that using raw format images, in ceph backed environments, is highly recommended because of this (or even that using qcow2 in ceph backed envs is very likely going to be bad) that would help.

Please let me know if you need any more information.

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Release: on 2020-05-28 17:21:12
SHA: 1c4ab4c62a31fc3b222e8736af8bfb1fff0b3c21
Source: https://opendev.org/openstack/openstack-manuals/src/doc/image-guide/source/windows-image.rst
URL: https://docs.openstack.org/image-guide/windows-image.html