Hi there, we are a storage vendor and have a large customer who is interested in using the Nova Compute charm with our storage, which we expose to OpenStack environments via Cinder or Manila. In reading the Nova Compute charm docs there appears to be some method of using Cinder behind Ceph RBD (though details are not clear to me) – but there appears to be no direct method to just consume Cinder (or Manila) in the context of that Charm. The customer would prefer to avoid Ceph in the middle if possible. Can you please help me understand the best path to accomplish that? Thanks!
If OpenStack (including Cinder) is deployed with the charms and if your storage solution provides block devices to the host running Cinder then it should work.
By default, Cinder provides volumes to OpenStack VMs using LVM and iSCSI.
Cinder (and Nova) can use Ceph RBD as a backend for volumes (Cinder) or for ephemeral storage (Nova).
This is a “built-in” feature of those charms but in no way mandatory, you could have a Nova/Cinder setup with no Ceph at all and only use Local, NAS or SAN storage, depending on how you configure Cinder with a supported backend.
Thanks folks. First, to confirm Hybrid512’s point, we understand it is possible to use OpenStack generally with Ceph, or without Ceph, as long as an appropriate Cinder backend is provided. (We have lots of experience with OpenStack in general, but are less familiar with the Canonical Charmed flavor.)
However, we see a lot of Ceph-related knobs exposed directly in the Nova Compute charm specifically. So we’re wondering if we’re missing similar general Cinder knobs in the Nova Compute charm, or if not, if there is documentation about how Cinder-based storage is configured when deploying with the Nova Compute charm specifically.