On Wed, Dec 6, 2017 at 9:13 PM, Jaze Lee <[email protected]> wrote: > 2017-12-07 7:12 GMT+08:00 Matt Riedemann <[email protected]>: >> On 12/6/2017 2:11 AM, 李杰 wrote: >>> >>> Hi,all >>> >>> Now the boot from volume 's instance of rebuild operation has a >>> problem.For example,after the rebuild operation,the instance 's root disk is >>> not replace. >>> I found the reason is that when we use the "_build_resources" function to >>> prepare source,it obtains the block devices according to the previous >>> instance 's uuid and attaches them to instance.So boot from volume 's >>> instance of rebuild operation doesn't update data. >>> To solve it,I plan to use CLI 's "metadata" option,to increase a >>> key name "source_type".The "source_type" includes "snapshot" and "image".We >>> can judge from "source_type".If the "source_type" is "snapshot",we can >>> transform the given snapshot to a volume and attach this volume to >>> instance.If the "source_type" is "image",we don't handle it. >>> Can you give me some advice?Help in troubleshooting this issue >>> will be appreciated. >>> >> >> See: https://review.openstack.org/#/c/520660/ >> >> We just started disallowing rebuilding a volume-backed instance where the >> image changes during the rebuild. We don't support it in the compute >> service, as you've found out, so we're going to make it a fast failure in >> the API. > > Well, are there some reasons for you want to disallowing rebuilding a > volume-backend instance. > Just give the the review is not a convincing answer. >
Rebuilding a volume-backed instance never worked. While the API currently accepts your request, nothing will happen. The instance won't be rebuilt as expected. There had been a couple of proposals/changes to add support: * https://review.openstack.org/#/c/442295/ * https://review.openstack.org/#/c/305079/ But technical challenges have been uncovered, making it harder to implement a proper solution. The change [1] linked by Matt Riedemann proposes failing rapidly so the user isn't under the false impression that a rebuild is being performed when in fact, nothing will happen. I do agree that being able to rebuild a volume-backed instance would be a great addition. We have been offering volume-backed instance for more than 4 years and our users love it. But for now, rebuild just doesn't work at all. It's better to send the right message through the API by failing fast. [1] https://review.openstack.org/#/c/520660/ -- Mathieu __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
