Open Stack

Hello,

I use Ceph as the storage backend for Nova, Glance, and Cinder.

If I create a snapshot for a instance, It create a new image in
glance. And I can use the image to create a new instance.

This feels to me more like creating an image based on the current
state of the VM rather than creating a VM snapshot.

I want to ask:
1、Can I create and revert a VM snapshot like I would in virtual
machine software?
2、When a VM uses multiple disks/volumes, does OpenStack support taking
a snapshot of all disks/volumes of the VM as a whole?
3、Can OpenStack snapshot and save the memory state of a VM?

If it is not currently supported, are there any simple customization
implementation ideas that can be recommended?

Thank you for any help and suggestions.
Best wishes.

Han