On Wed, Oct 12, 2016 at 7:10 AM, Giulio Fidente <[email protected]> wrote: > hi, > > we introduced support for the deployment of Ceph in the liberty release so > that it could optionally be used as backend for one or more of Cinder, > Glance, Nova and more recently Gnocchi. > > We used to deploy Ceph MONs on the controller nodes and Ceph OSDs on > dedicated ceph-storage nodes so a deployment of OpenStack with Ceph would > need at least 1 more additional node to host a Ceph OSD. > > In our HA scenario the storage backends are configured as follows: > > Glance -> Swift > Nova (ephemeral) -> Local > Cinder (persistent) -> LVM (on controllers) > Gnocchi -> Swift > > The downside of the above configuration is that Cinder volumes can not be > replicated across the controller nodes and become unavailable if a > controller fails, while production environments generally expect persistent > storage to be highly available. Cinder volumes instead could even get lost > completely in case of a permanent failure of a controller. > > With the Newton release and the composable roles we can now deploy Ceph OSDs > on the compute nodes, removing the requirement we had for an additional node > to host a Ceph OSD. > > I would like to ask for some feedback on the possibility of deploying Ceph > by default in the HA scenario and use it as backend for Cinder. > > Also using Swift as backend for Glance and Gnocchi is enough to cover the > availability issue for the data, but it also means we're storing that data > on the controller nodes which might or might not be wanted; I don't see a > strong reason for defaulting them to Ceph, but it might make more sense when > Ceph is available; feedback about this would be appreciated as well. > > Finally a shared backend (Ceph) for Nova would allow live migrations but > probably decrease performances for the guests in general; so I'd be against > defaulting Nova to Ceph. Feedback?
+1 on making ceph default backend for nova/glance/cinder/gnocchi. I think this is the most common use-case we currently have in our deployments AFIK. Also, I'll continue to work on scenarios jobs (scenario002 and scenario003 without Ceph to cover other use cases). > -- > Giulio Fidente > GPG KEY: 08D733BA > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: [email protected]?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Emilien Macchi __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
