Create Glance Snapshot
Via Horizon Dashboard
- Navigate to Project → Compute → Instances.
- Locate the instance you want to snapshot.
- In the Actions column, click the dropdown menu next to the instance and select Create Snapshot.
- Enter a Snapshot Name and click Create Snapshot.
- The snapshot will appear under Project → Compute → Images.
Via CLI
openstack server image create <instance_id> --name <snapshot_name>
- If the instance has attached volumes, corresponding Cinder volumes will be created.
- If the instance was booted from a volume, the snapshot will show a size of 0 and contain only metadata.
Create Volume from Snapshot
If the instance was booted from a volume and you want to store the root disk in the image repository, first you need to create volume from snapshot:
Via Horizon Dashboard
- Go to Project → Compute → Volumes → Snapshots.
- Find the snapshot and select Create Volume from the action menu.
- Provide a name for the volume and confirm.
Via CLI
openstack volume create --snapshot <snapshot_id> <volume_name>
Uploading a Volume to Glance as an Image
Via Horizon Dashboard
- Navigate to Project → Compute → Volumes.
- Locate the desired volume, and in the Actions column, select Upload to Image.
- Provide an Image Name, choose a Disk Format, and click Upload.
Via CLI
openstack image create --volume <volume_id> <image_name>
Restoring an Instance from a Snapshot
Via Horizon Dashboard
- Navigate to Project → Compute → Instances.
- Click Launch Instance.
- In the Source tab, select Image and choose the desired snapshot.
- Complete the remaining fields (e.g., flavor, network) and click Launch Instance.
Via CLI
openstack server create --image <snapshot_id> --flavor <flavor_id> <new_instance_name>
Key Notes
- Snapshots of instances booted from volumes will have 0 size in Glance and contain only metadata.
- To store a root disk from a volume in Glance, you must first create a volume from the snapshot, then upload it to Glance as an image.
- Glance snapshots and images are periodically backed up into a tape archive for long-term protection.