On Wednesday, October 12, 2016, Emilien Macchi <[email protected]> wrote:
> On Wed, Oct 12, 2016 at 7:10 AM, Giulio Fidente <[email protected] > <javascript:;>> 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. + 1 from me. Ceph is the recommended backend for gnocchi and this will help a lot with some recent performance issue we have seen. - Prad > 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 >
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