Good Day
From documentation we are able to understand that we can configure multiple backends for cinder (Ceph ,External Storage device or NFS etc)Is there any way we can choose the backend while instance launching .Say instance1 backend should be from an external storage device like EMC and instance2 to launch and have backend volume from ceph .Can this be achieved using cinder availability zone implementation or any other way?
I have gone through below link (section Configure Block Storage scheduler multi back end)
Suggestions please ..
Regards,Deepa K R
Hi Deepa,
Backend selection is controlled by the scheduler, with the end user being able to choose different volume types configured by the administrator to tell the scheduler what characteristics are needed for the selected storage.
The Volume Type section in the Multibackend docs briefly describe some of this:
https://docs.openstack.org/cinder/latest/admin/blockstorage-multi-backend.html#volume-type
These volume types can be configured with extra specs the explicitly declare a specific backend name to use for creating volumes of that type, or it can contain extra specs that just define other properties (such as just stating the protocol needs to be iscsi) and the scheduler will use those to decide where to place the volume.
Some description of defining availability zones in extra specs (which I'm seeing could really use some updates) can be found here:
https://docs.openstack.org/cinder/latest/admin/blockstorage-availability-zone-type.html
From the command line, you can also explicitly state which availability zone you want the volume created in. See bullets 2 and 3 here:
https://docs.openstack.org/cinder/latest/cli/cli-manage-volumes.html#create-a-volume
Good luck!
Sean