Hi,

it's always glance that serves the images, it just depends on how you 
decide to create the instance, ephemeral or persistent disks. You can 
find more information about storage concepts in [1].

If I'm not completely wrong, since Newton release the default in the 
Horizon settings is to create an instance from volume, so it would be 
a persistent disk managed by cinder (the volume persists after the 
instance has been deleted, this is also configurable). The image is 
downloaded from glance into a volume on your volume server.

If you change the Horizon behavior or if you launch an instance from 
the cli you'd get an ephemeral disk by nova, depending on your storage 
backend this would be a local copy of the image on the compute node(s) 
or something related in your storage backend, e.g. an rbd object in 
ceph.

Does this clear it up a bit?

Regards,
Eugen

[1] 
https://docs.openstack.org/arch-design/design-storage/design-storage-concepts.html


Zitat von Jyoti Dahiwele <jyotishri403@gmail.com>:

> Dear Team,
>
> Please clear me my following doubts.
> When I use image from source option  and mini flavor to create an instace,
> from which storage pool instance will get root disk ? From cinder or glance?