Hello Cephers ! After having read since Luminuous that EC pools are now supported for writable RBD pools, I decided to use it in a new OpenStack Cloud deployment. The gain on storage is really noticeable, and I want to reduce the storage cost. So I decided to use ceph-ansible to deploy the Ceph Cluster (Mimic 13.2.0), and openstack-ansible for the OpenStack (Queens) parts. Since I started, I had some surprises : 1) ceph-ansible (stable-3.1) does not handle correctly EC pool creation. I had to modify the parameters order in the ansible role that launch rbd commands (OpenStack pool creation). 2) After deploying OpenStack, I try to load Glance images without success. First, I forgot to enable write on the EC pool (ceph-ansible does not). And then, I found that we cannot use directly an EC pool, but have to use a replicated one, backed by an EC pool for data. Indeed, it is documented here, but I haven't read it until now : http://docs.ceph.com/docs/master/rados/operations/erasure-code/? highlight=erasure#erasure-coding-with-overwrites 3) OpenStack and so openstack-ansible, cannot be configured to specify this data pool By chance, I found that link : https://www.reddit.com/r/ceph/comments/72yc9m/ceph_openstack_with_ec/ So it's possible to use the Ceph user default config to have a default data pool, used by glance, cinder, nova users. I still have to search if ceph-ansible will help me to configure that. Now, I wonder what other surprises I will face. Does someone have used EC pools with OpenStack in production ? I've read that small writes performances are not good for example. Ah, and just a little more question : can we do copy on write between an EC pool and a replicated one ? If I store my OpenStack Images in Glance on an EC pool and then I create an instance on a replicated one (a performance oriented Cinder pool). Please share your experience about EC pools and OpenStack ! Thanks, -- Gilles _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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