Comment 7 for bug 1947518

We have been also hit this issue.

After upgrading openstack volume from image creation fails. This means new instances also fail.
I have been debugging this issue because it was also affecting us after upgrading openstack and getting the new cinder code that corrects the problem with the stripe unit (in cinder it uses by default 8MB but in glance it uses 4MB).

The problem is that the new fix has an important error because it tries to open the glance image in read-write mode (which is the default in rbd.Image).

So the correct way it would be to open it using:

image = self.rbd.Image(ioctx, volume_name, read_only=True)

You must explicitly set the read_only=True (by default is False).

I have just sent a PR to fix this issue:

https://review.opendev.org/c/openstack/cinder/+/815701

I think the importance should be raised to critical because it will break current installs after upgrading causing a great pain between sysadmins.