Open Stack

Hello everyone.

We are updating our public images regularly (to provide them to 
customers in up-to-date state). But there is a problem: If some instance 
starts from image it becomes 'used'. That means:
* That image is used as _base for nova
* If instance is reverted this image is used to recreate instance's disk
* If instance is rescued this image is used as rescue base
* It is redownloaded during resize/migration (on a new compute node)

One more (our specific):
We're using raw disks with _base on slow SATA drives (in comparison to 
fast SSD for disks), and if that SATA fails, we replace it (and nova 
redownloads stuff in _base).

If image is deleted, it causes problems with nova (nova can't download 
_base).

The second part of the problem: glance disallows to update image (upload 
new image with same ID), so we're forced to upload updated image with 
new ID and to remove the old one. This causes problems described above. 
And if tenant boots from own snapshot and removes snapshot without 
removing instance, it causes same problem even without our activity.

How do you handle public image updates in your case?

Thanks!