2017-12-07 10:27 GMT+08:00 Mathieu Gagné <[email protected]>: > 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/
Oh, I think it is not a proper solution. Adding a fast failure is much easier than to support rebuilding of volume-backend instance. I found the last reason to abandon the review at https://review.openstack.org/#/c/305079/ is because the design is not very clear and lack of bp. So everyone who wants to add this feature to nova is welcome. Please go ahead. > > -- > Mathieu > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: [email protected]?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- 谦谦君子 __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
