Re: [openstack-dev] [Glance] Recall for previous iscsi backend BP
It is quite possible that the requirement for glance to own images can be achieved by having a glance tenant in cinder, and using clone and volume-transfer functionalities in cinder to get copies to the right place. I know there is some attempts to move away from the single glance tenant model for swift usage, but doing anything else in cinder will require significantly more thought/ On 19 November 2014 23:04, Alex Meade mr.alex.me...@gmail.com wrote: Hey Henry/Folks, I think it could make sense for Glance to store the volume UUID, the idea is that no matter where an image is stored it should be *owned* by Glance and not deleted out from under it. But that is more of a single tenant vs multi tenant cinder store. It makes sense for Cinder to at least abstract all of the block storage needs. Glance and any other service should reuse Cinders ability to talk to certain backends. It would be wasted effort to reimplement Cinder drivers as Glance stores. I do agree with Duncan that a great way to solve these issues is a third party transfer service, which others and I in the Glance community have discussed at numerous summits (since San Diego). -Alex On Wed, Nov 19, 2014 at 3:40 AM, henry hly henry4...@gmail.com wrote: Hi Flavio, Thanks for your information about Cinder Store, Yet I have a little concern about Cinder backend: Suppose cinder and glance both use Ceph as Store, then if cinder can do instant copy to glance by ceph clone (maybe not now but some time later), what information would be stored in glance? Obviously volume UUID is not a good choice, because after volume is deleted then image can't be referenced. The best choice is that cloned ceph object URI also be stored in glance location, letting both glance and cinder see the backend store details. However, although it really make sense for Ceph like All-in-one Store, I'm not sure if iscsi backend can be used the same way. On Wed, Nov 19, 2014 at 4:00 PM, Flavio Percoco fla...@redhat.com wrote: On 19/11/14 15:21 +0800, henry hly wrote: In the Previous BP [1], support for iscsi backend is introduced into glance. However, it was abandoned because of Cinder backend replacement. The reason is that all storage backend details should be hidden by cinder, not exposed to other projects. However, with more and more interest in Converged Storage like Ceph, it's necessary to expose storage backend to glance as well as cinder. An example is that when transferring bits between volume and image, we can utilize advanced storage offload capability like linked clone to do very fast instant copy. Maybe we need a more general glance backend location support not only with iscsi. [1] https://blueprints.launchpad.net/glance/+spec/iscsi-backend-store Hey Henry, This blueprint has been superseeded by one proposing a Cinder store for Glance. The Cinder store is, unfortunately, in a sorry state. Short story, it's not fully implemented. I truly think Glance is not the place where you'd have an iscsi store, that's Cinder's field and the best way to achieve what you want is by having a fully implemented Cinder store that doesn't rely on Cinder's API but has access to the volumes. Unfortunately, this is not possible now and I don't think it'll be possible until L (or even M?). FWIW, I think the use case you've mentioned is useful and it's something we have in our TODO list. Cheers, Flavio -- @flaper87 Flavio Percoco ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Duncan Thomas ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [Glance] Recall for previous iscsi backend BP
On 19/11/14 15:21 +0800, henry hly wrote: In the Previous BP [1], support for iscsi backend is introduced into glance. However, it was abandoned because of Cinder backend replacement. The reason is that all storage backend details should be hidden by cinder, not exposed to other projects. However, with more and more interest in Converged Storage like Ceph, it's necessary to expose storage backend to glance as well as cinder. An example is that when transferring bits between volume and image, we can utilize advanced storage offload capability like linked clone to do very fast instant copy. Maybe we need a more general glance backend location support not only with iscsi. [1] https://blueprints.launchpad.net/glance/+spec/iscsi-backend-store Hey Henry, This blueprint has been superseeded by one proposing a Cinder store for Glance. The Cinder store is, unfortunately, in a sorry state. Short story, it's not fully implemented. I truly think Glance is not the place where you'd have an iscsi store, that's Cinder's field and the best way to achieve what you want is by having a fully implemented Cinder store that doesn't rely on Cinder's API but has access to the volumes. Unfortunately, this is not possible now and I don't think it'll be possible until L (or even M?). FWIW, I think the use case you've mentioned is useful and it's something we have in our TODO list. Cheers, Flavio -- @flaper87 Flavio Percoco pgps0pmEesXKz.pgp Description: PGP signature ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [Glance] Recall for previous iscsi backend BP
I think that having a stand-alone (client of cinder) rich data streaming service (http put/get with offset support, which can be used for conventional glance plus volume upload/download directly), and rich data-source semantics exposed so that it can be used in an optimal way by/for nova, need not wait on the cinder roadmap to be realised, and is ultimately the right way to progress this. Certain features may need to wait for cinder features (e.g. read-only multi-attach is not available yet), but the basic framework could be written right now, I think On 19 November 2014 10:00, Flavio Percoco fla...@redhat.com wrote: On 19/11/14 15:21 +0800, henry hly wrote: In the Previous BP [1], support for iscsi backend is introduced into glance. However, it was abandoned because of Cinder backend replacement. The reason is that all storage backend details should be hidden by cinder, not exposed to other projects. However, with more and more interest in Converged Storage like Ceph, it's necessary to expose storage backend to glance as well as cinder. An example is that when transferring bits between volume and image, we can utilize advanced storage offload capability like linked clone to do very fast instant copy. Maybe we need a more general glance backend location support not only with iscsi. [1] https://blueprints.launchpad.net/glance/+spec/iscsi-backend-store Hey Henry, This blueprint has been superseeded by one proposing a Cinder store for Glance. The Cinder store is, unfortunately, in a sorry state. Short story, it's not fully implemented. I truly think Glance is not the place where you'd have an iscsi store, that's Cinder's field and the best way to achieve what you want is by having a fully implemented Cinder store that doesn't rely on Cinder's API but has access to the volumes. Unfortunately, this is not possible now and I don't think it'll be possible until L (or even M?). FWIW, I think the use case you've mentioned is useful and it's something we have in our TODO list. Cheers, Flavio -- @flaper87 Flavio Percoco ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Duncan Thomas ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [Glance] Recall for previous iscsi backend BP
Hi Flavio, Thanks for your information about Cinder Store, Yet I have a little concern about Cinder backend: Suppose cinder and glance both use Ceph as Store, then if cinder can do instant copy to glance by ceph clone (maybe not now but some time later), what information would be stored in glance? Obviously volume UUID is not a good choice, because after volume is deleted then image can't be referenced. The best choice is that cloned ceph object URI also be stored in glance location, letting both glance and cinder see the backend store details. However, although it really make sense for Ceph like All-in-one Store, I'm not sure if iscsi backend can be used the same way. On Wed, Nov 19, 2014 at 4:00 PM, Flavio Percoco fla...@redhat.com wrote: On 19/11/14 15:21 +0800, henry hly wrote: In the Previous BP [1], support for iscsi backend is introduced into glance. However, it was abandoned because of Cinder backend replacement. The reason is that all storage backend details should be hidden by cinder, not exposed to other projects. However, with more and more interest in Converged Storage like Ceph, it's necessary to expose storage backend to glance as well as cinder. An example is that when transferring bits between volume and image, we can utilize advanced storage offload capability like linked clone to do very fast instant copy. Maybe we need a more general glance backend location support not only with iscsi. [1] https://blueprints.launchpad.net/glance/+spec/iscsi-backend-store Hey Henry, This blueprint has been superseeded by one proposing a Cinder store for Glance. The Cinder store is, unfortunately, in a sorry state. Short story, it's not fully implemented. I truly think Glance is not the place where you'd have an iscsi store, that's Cinder's field and the best way to achieve what you want is by having a fully implemented Cinder store that doesn't rely on Cinder's API but has access to the volumes. Unfortunately, this is not possible now and I don't think it'll be possible until L (or even M?). FWIW, I think the use case you've mentioned is useful and it's something we have in our TODO list. Cheers, Flavio -- @flaper87 Flavio Percoco ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [Glance] Recall for previous iscsi backend BP
Hey Henry/Folks, I think it could make sense for Glance to store the volume UUID, the idea is that no matter where an image is stored it should be *owned* by Glance and not deleted out from under it. But that is more of a single tenant vs multi tenant cinder store. It makes sense for Cinder to at least abstract all of the block storage needs. Glance and any other service should reuse Cinders ability to talk to certain backends. It would be wasted effort to reimplement Cinder drivers as Glance stores. I do agree with Duncan that a great way to solve these issues is a third party transfer service, which others and I in the Glance community have discussed at numerous summits (since San Diego). -Alex On Wed, Nov 19, 2014 at 3:40 AM, henry hly henry4...@gmail.com wrote: Hi Flavio, Thanks for your information about Cinder Store, Yet I have a little concern about Cinder backend: Suppose cinder and glance both use Ceph as Store, then if cinder can do instant copy to glance by ceph clone (maybe not now but some time later), what information would be stored in glance? Obviously volume UUID is not a good choice, because after volume is deleted then image can't be referenced. The best choice is that cloned ceph object URI also be stored in glance location, letting both glance and cinder see the backend store details. However, although it really make sense for Ceph like All-in-one Store, I'm not sure if iscsi backend can be used the same way. On Wed, Nov 19, 2014 at 4:00 PM, Flavio Percoco fla...@redhat.com wrote: On 19/11/14 15:21 +0800, henry hly wrote: In the Previous BP [1], support for iscsi backend is introduced into glance. However, it was abandoned because of Cinder backend replacement. The reason is that all storage backend details should be hidden by cinder, not exposed to other projects. However, with more and more interest in Converged Storage like Ceph, it's necessary to expose storage backend to glance as well as cinder. An example is that when transferring bits between volume and image, we can utilize advanced storage offload capability like linked clone to do very fast instant copy. Maybe we need a more general glance backend location support not only with iscsi. [1] https://blueprints.launchpad.net/glance/+spec/iscsi-backend-store Hey Henry, This blueprint has been superseeded by one proposing a Cinder store for Glance. The Cinder store is, unfortunately, in a sorry state. Short story, it's not fully implemented. I truly think Glance is not the place where you'd have an iscsi store, that's Cinder's field and the best way to achieve what you want is by having a fully implemented Cinder store that doesn't rely on Cinder's API but has access to the volumes. Unfortunately, this is not possible now and I don't think it'll be possible until L (or even M?). FWIW, I think the use case you've mentioned is useful and it's something we have in our TODO list. Cheers, Flavio -- @flaper87 Flavio Percoco ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
