The option1 is a bad idea, IMO. Think about so many extra_specs in the flavor today, you really don't want create another dozen of flavor with root_gb=0 just for booting from volume.
For the billing concern, it really should be taken into account, but it's not the business of OpenStack, IMHO. I agree with Jay, option 2 will be good. 2015-03-05 13:58 GMT+08:00 Alex Xu <sou...@gmail.com>: > > > 2015-03-04 4:45 GMT+08:00 Jay Pipes <jaypi...@gmail.com>: >> >> On 03/03/2015 01:10 AM, Rui Chen wrote: >>> >>> Hi all, >>> >>> When we boot instance from volume, we find some ambiguous description >>> about flavor root_gb in operations guide, >>> http://docs.openstack.org/openstack-ops/content/flavors.html >>> >>> /Virtual root disk size in gigabytes. This is an ephemeral disk the base >>> image is copied into. You don't use it when you boot from a persistent >>> volume. / >>> /The "0" size is a special case that uses the native base image size as >>> the size of the ephemeral root volume./ >>> / >>> / >>> 'You don't use it(root_gb) when you boot from a persistent volume.' >>> It means that we need to set the root_gb to 0 or not? I don't know. >> >> >> Hi Rui, I agree the documentation -- and frankly, the code in Nova -- is >> confusing around this area. >> >>> But I find out that the root_gb will been added into local_gb_used of >>> compute_node so that it will impact the next scheduling. Think about a >>> use case, the local_gb of compute_node is 10, boot instance from volume >>> with the root_gb=5 flavor, in this case, I can only boot 2 >>> boot-from-volume instances on the compute_nodes, although these >>> instances don't use the local disk of compute_nodes. >>> >>> I find a patch that try to fix this issue, >>> https://review.openstack.org/#/c/136284/ >>> >>> I want to know that which solution is better for you? >>> >>> Solution #1: boot instance from volume with the root_gb=0 flavor. >>> Solution #2: add some special logic in order to correct the disk usage, >>> like patch #136284 >> >> >> Solution #2 is a better idea, IMO. There should not be any "magic" setting >> for root_gb that needs to be interpreted both by the user and the Nova code >> base. >> >> The issue with the 136284 patch is that it is trying to address the >> problem in the wrong place, IMHO. > > > Emm.....I'm thinking of one case. There two flavors, one with root_gb=0, > another one with root_gb=10. And user choice different flavor will pay > different money. > If user choice the flavor with root_gb=10, and then boot from volume...then > user still need pay the extra money. That's good strange. Or say we should > let the bill system to distinguish the instance is boot from volume or not. > Or say we just tell user you make wrong choice... For this case, should we > choice > solution #1? > >> >> >> Best, >> -jay >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > -- Regards! ----------------------------------- Lingxian Kong __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
