<div dir="ltr">Hi All,<div><br></div><div>Currently, we have strong demands about "rebuilding"(or actions like rebuilding) volume-backed instances. As in production deployment, volume backed instance is widely used. Users have the demands of performing the rebuild(recovery) action for root device while maintain instance UUID sorts of information, many users also wants to keep the volume uuid unchanged.</div><div><br></div><div>Nova side doesn't support using Rebuild API directly for volume backed instances (the volume will not change). And Nova side also doesn't support detaching root device, that means we cannot performing volume backup/restore from cinder side, because those actions needs the volume in "available" status. </div><div><br></div><div>Now there are couple of patches proposed in nova trying to fix this problem:</div><div><span style="font-family:Arial,sans-serif;font-size:10pt">[1] <a href="https://review.openstack.org/#/c/201458/">https://review.openstack.org/#/c/201458/</a></span> </div><div><span style="font-family:Arial,sans-serif;font-size:10pt">[2] <a href="https://review.openstack.org/#/c/221732/">https://review.openstack.org/#/c/221732/</a></span> <br></div><div>[3] <a href="https://review.openstack.org/#/c/223887/">https://review.openstack.org/#/c/223887/</a></div><div><br></div><div>[1] and [2] are trying to expose the API of detaching root devices, [3] is trying to fix it in the current Rebuild API. But yet none of them got much attention.</div><div><br></div><div>As we now have strong demand on performing the "rebuilding" action for volume-backed instances, and yet there is not any clear information about  it. I wonder is there any plans of how to support it in Nova and Cinder?</div><div><br></div><div>Yours,</div><div><br></div><div>Zheng</div></div>